It was the notion of discovery that occurred with the Rei Marti water deposit, a former space for water storage of the Torre Bellesguard house in Barcelona, designed by Gaudi and located next to the viaduct that is also attributed to this totemic architect. This water deposit had been concealed beneath a pine forest until 20 years ago, when during some minor maintenance work on the small part of the old-growth forest that still remained; a truck began to sink into the ground. Quickly it was confirmed to the amazement of all that a huge space of more than 600 m2 was crouching under the earth. It was definitely decided to share the space, to invite the public to reclaim this stroke of luck, but, above all, share the emotion of the unexpected discovery. To this end the project had to be as faithful as possible to the space as it was originally encountered. The character, materiality, the force of a space with arches and vaults had to be valued, maintained and strengthened by the intervention.