Italy’s Collepardo Caves have been given a mystic, ethereal new lighting scheme from OkiDoki Arkitekter that highlights the naturally-formed caverns, while protecting the thriving ecosystem within.

Located in the Frosinone province of Italy, around 70km from Rome, lie the Collepardo Caves. A site of significant ecological and archaeological interest, the underground labyrinth is home to a diverse assortment of natural resources, wildlife and plant life.

Under the supervision of Albino Ruberti, Head of the Cabinet of the Lazio region, and the region’s Cultural Heritage Department, the caves have been given a new lighting scheme that brings a sense of mystique and drama, while protecting the delicate ecosystem.

Stockholm-based, Italian lighting designer Chiara Carucci of OkiDoki Arkitekter, was approached by Ruberti to take on the challenge of illuminating the space in a respectful manner.

“I was ecstatic to be offered the project, especially after visiting the caves for the first time; but I only accepted after making sure that we could respect the heritage of the caves,” she said. “Too many touristic caves around the world are lit like an amusement park for the sake of tourism, with no respect for the biodiversity.”

The aim for the new lighting was therefore twofold, as Carucci explained: “Initially the main goal was to seduce tourists, therefore giving a new input to the local economy; but also, to enhance the beauty while protecting the heritage.

“My interpretation of these goals, shared and agreed in several meetings with the client [Lazio Region and LazioCrea, particularly Director Maurizio Stumbo and Laure Maurizet], was not related to the so-called “wow factor”, nor the Instagrammability of the project. I meant to convey one simple message: respect the heritage.

“I was hoping that through a simple yet incisive lighting design, I could inspire people to look beyond. If I could seduce them, maybe scare them a bit too, and revive the spirit of adventure we always have, at least until adulthood, they would hopefully be inspired to respect and love nature.”

Within this “biodiversity treasure”, as Carucci described it, lives a large community of bats, including at least five species. Falling under the “Habitat Directive” on the conservation of natural habitats and of wild fauna and flora, it was therefore vital that any lighting interventions do not disturb this vibrant colony. Further to this, Carucci had to ensure that the new lighting limited the ecological problem of lampenflora – the proliferation of principally phototrophic organisms near artificial light sources at sites where under natural circumstances they would not appear.

Luckily for Carucci, she was given guidance from multiple sources when developing the lighting concept: “Vito Consoli, Regional Director for Natural Heritage and Protected Natural Areas, was extremely supportive. He shared a wide bibliography about chiroptera [bats], lampenflora and touristic caves,” she said. “‘Get informed before doing’ has always been my way of working, and I’ve never felt so encouraged as I did here.”

“The guides also shared their experience and love for the place with me, as well as a lot of knowledge. When I first met them, I hoped that I could replicate their genuineness in my design.”

To help get into the zone while developing the lighting concept, Carucci rented a flat in Collepardo with friend and architect Ruggero di Maio, who has a lot of experience in construction site management. Here, she “lived and breathed the atmosphere, slow pace and the mood of the village,” immersing herself into the locale to better understand it.

“The way the daylight brings to life the beautiful cliffs, woods, nature reserves and rivers, helped me to build the concept. I felt that I could enhance the caves through effects of light that I experienced in the area,” she explained.

“I used the long shadows and soft contrasts of central Italian afternoons to enhance several speleothems, through side light and medium beam lighting fixtures. I looked at the glistening on the Torrente Cosa river for gently treating the splattermites, which are active and yet so fragile. I was inspired by the sharp morning sunrays through the hillside for enhancing the depth of the cave, while keeping several areas darker, providing comfortable aerial corridors for the bats. I looked at the midday sun in the clearings and the woods for more contrasting effects, especially for the entrance. Finally, the sunset that would make a golden “explosion” on the steep cliff in front of the cave, is my main inspiration for the lighting of the detachment fault.”

Throughout the project, Carucci was in close communication with an extensive team of researchers, scientists, and advisers, who provided guidance on what lighting scenarios would best protect the habitat within the caves.

“This was one of the most challenging and interesting aspects of the project,” she explained. “From the beginning we had invaluable support from Giovanni Mastrobuoni, LazioCrea’s consultant for chiroptera, who has been studying the local colonies for the past year.

“My ‘voyage au centre de la terre’ continued with researchers Leonardo Ancillotto, Rosangela Addesso and Jo De Waele. We met several times, online and in person, and their input and reports were extremely valuable.

“Particularly, Rosangela and I discussed the use of specific wavelengths of light spectrum that would reduce the development of lampenflora – after careful evaluation, we agreed to work on three parameters: distance, low intensity, and total time of operations.”

Practically, this meant that fixtures were installed 800mm from speleothems (mineral formations), with very low lumen outputs and short operating times. It was also suggested to avoid illuminating soft surfaces and those covered with vermiculation, with lighting instead focused on rocks and crystalline solids.

Bearing these suggestions in mind, one of the core facets of Carucci’s design was to keep the lighting deliberately minimal, and purposefully dark, with a respectful approach more akin to illuminating delicate artefacts in a museum. “I completed the design with 89 lighting fixtures [excluding the handrail lighting], 64 of which deliver 160lm, 1.5W each, and I dimmed several of these down to 50% when in use, so it’s pretty dark!

“Some may think that a place must be bright to be awesome, but in my opinion it all depends on both the context and the education of the visitors,” she said.

“Especially after electrification, caves became tourist attractions, however they are naturally dark. Since we could inform the public, before and during the visit, I decided to work with low intensities, not only for environmental reasons. I used an entire palette of effects (light, shadows, contrast, colour temperature, etc) when and where necessary, and worked with perception to achieve a three-dimensional vision that supports storytelling and narrative and creates an experience for visitors.

“The darker, almost mystical atmosphere may make visitors feel like explorers and support the mood for listening and learning.”

To further enhance this atmosphere, Carucci created a series of lighting scenes to showcase the various spaces within the cave. This also helped to create a natural flow for visitors, guiding them through the caves in a sequence that would follow the new accompanying audio guide, delivered by President of WWF Italy and local TV personality, Donatella Bianchi.

“Besides practical suggestions, the researchers supported my effort in having ‘time’ as a key aspect of the design,” she said. “I interviewed all the guides, getting info on visit durations, number of people per group, and their ‘highlights’. From there, the narrative and landscape suggested to divide the caves into five zones or thematic areas, so that I could reveal the caves’ marvels gradually through five corresponding light scenes, activated as visitors pass by.”

The first scene, the entrance, is strongly characterised by daylight for most of the day, so Carucci had to find a balance between variable light levels and safety needs while creating anticipation. “Daylight was a key inspiration for my design, but also a constraint – it truly influenced my design,” she said.

Visitors adapt to the darkness as they move towards the inner part of the cave; as their vision adjusts, they discover more details. The walking path is uniformly lit depending on the level of natural light, with fixtures recessed into the handrails. Lumen output was kept deliberately low, with levels dimming down further once visitors pass by, until the first “stop”, where sensors activate the second scene: the Stalagmites. Here, visitors gain a better view of the complexity of the cave and can spot the parallel between the daylight and the new interior lighting.

The third scene, The Cathedral, is the lowest part of the cave. Here, the lighting was designed to make visitors feel very small, compared to the stalagmites and columns, and to experience the silence. “Just like in a gothic cathedral, people should just be in reverence and awe,” Carucci continued.

“I had the chance to keep lighting levels very low, especially since daylight is rarely visible from this area. However, the transition to the fourth scene is majestic – in 20 second fades, the detachment fault is revealed, as well as the most active part of the cave, the splattermites.”

The main visiting area of the cave, The Terrace, is a large space where people can spend more time, admiring the complexity and extension of the cave. Here, the play and juxtaposition with the daylight is fundamental, revealing the arches and telling the story of the formation of the cave.

When the group is almost ready to leave, the guides then turn off several light fixtures, and activate a holographic projection while the audio guide talks more about the cave and its inhabitants.

The final lighting scene sees the lighting for large parts of the cave gradually turn off, and as visitors adapt to the lower light levels, they experience a semi-blackout, turning the darkness into a resource for storytelling.

On top of the need to be respectful of the caves’ delicate ecosystem, Carucci revealed that the sheer logistics of illuminating the space, from planning and mock-ups to fixture placement, was one of the biggest challenges that she faced.

“I wanted to protect the cave’s fragile ecosystem through a careful plan for the installation: lighting fixtures would be mounted on the existing handrails, or placed on areas of collapse, or areas disturbed by previous works or human intervention. However, in order to limit new intervention and the amount of alien materials brought into the caves, I also had to find a compromise between quantity of fixtures and quality of lighting for each area.

“I found it more practical to create the concept through a complete test lighting, while relying on my personal experience and sensibility. Besides the compromises on quantity and quality, I also had to consider space for visiting and for mounting, while working with perception.

“Moreover, explaining the concept to the client is usually very complex, almost impossible in this context, without a full-scale mock-up. So, after testing the entire cave, I set up the lighting for the Cathedral, and invited the client in to experience it in person.

“In three weeks, I broke several gloves and two pairs of mountain shoes, my muscles hurt as I was not used to climbing. But the test lighting was a key experience, and the mock-up was fundamental to get the client’s approval.”

Although faced with multiple issues throughout the project, Carucci said that she is “usually motivated by challenging situations”.

“The collaboration with LazioCrea’s maintenance team and Ruggero di Maio during test lighting, with electrical engineer Massimiliano Faina on the design development, the client and the entire team of researchers was key for a successful process. Especially when working very long hours, admitting when you need help is fundamental.”

With the complexity that working in a cave with such a dense, thriving ecosystem brings, it is a far cry from what one may consider a typical architectural lighting project. However, Carucci believes that this project is what her lighting career has been building towards.

“Looking back, it seems that I prepared for this project for my entire career. Examining the effect of light on the ruins of a Roman villa in one of my first junior experiences in 2004; the special attention to conservation issues and details, learned from my mentors in several projects in Milan and abroad; my most recent experience in landscape lighting, especially in Eskilstuna, Sweden, built up a basis for taking on this project.

“However, none of the projects that I have worked on so far compared to the honour and challenges that I had here. For example, I usually design accessories for installation, especially for heritage buildings. In the caves, mounting also means noise. When designing bases and bollards for mounting fixtures off-path, I had to choose between including an extraneous material, such as concrete for the foundations, versus disrupting the ground with perforations. After consulting with the researchers, I decided for the latter – the drilling produces noise, but speeds up the installation process, and allows a higher flexibility in the aiming of the fixtures.

“Even the construction process was completely different, especially for the times and methods of installation: the building site was planned in relation to the bats’ phenological phases, starting after hibernation and concluding before the nursery.”

Despite some testing circumstances, the project was completed earlier this year, and Carucci explained that the new lighting has been very greatly received by tourists, guides, and researchers alike.

“The tourist feedback is gratifying, especially their silence during scene three, their surprised expression in scene four and their awe at the semi-blackout of scene five. But the most rewarding feeling is the joy and pride of the guides, who now introduce the caves feeling like owners of the project. The guides have been my most valuable asset and their approval and enthusiasm means everything.

“The researchers, especially Giovanni, highlighted how the lighting design sheds a new light on to the authentic spectacle of the site by supporting the visiting experience, while protecting its biodiversity.”

Indeed, while caves naturally have a mystic aura surrounding them, the new lighting within the Collepardo Caves helps to emphasise the wonder of the naturally formed caverns and formations, while respecting the wildlife that call the caves home.

“I take pride in the transformation, especially related to the quality of perception, towards a more natural look based upon a conscious use of darkness as a tool for design, that gives the space a mysterious charm, seducing visitors,” Carucci concluded.

“The lighting not only enhances the landscape and the intrinsic beauty of the caves, but also communicates the values of its heritage, and our care and our effort towards stewardship.”

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