The so-called Casa Sperimentale (ital. for ‘experimental house’) in the pine grove of Fregene was built as a concrete tree house by an architect family (Guiseppe Perugini, Uga de Plaisant and son Raynaldo Perugini).

The house consists of three independent buildings: the main house Casa Sperimentale, the Sphere, a separate guest house, and a curved concrete perimeter fence which surrounds the site.

The building is characterized by raw concrete modules and beams which are sliding into each other. Everything is floating above the ground on an alike interlaced pile construction. With its concrete branches, it reflects the structure of the forest.

The design approach for the house followed less the brutalist one, but more the ideas of APAO, the Association for Organic Architecture which was founded in 1944 by Perugini and Bruno Zevi.

Vacant, dilapidated. The building often falls victim for vandalism and gets used as canvas for graffiti. Some of the concrete superstructure’s metal couplings start to show structural failure. There have been several efforts made to save the building, but so far its future is uncertain.