Spanish design firm SelgasCano has completed the surreal Plasencia conference center and auditorium in Spain. Shaped like a giant boulder, the multifaceted building is wrapped in a translucent skin of ETFE panels that floods the interior with natural light during the day and glows like a lantern when illuminated from within at night. In contrast to its pale exterior, the interior is dominated with vibrant colors — from a bright orange entry hall to a deep red auditorium — that heighten the structure’s ethereal feel.

geometric building with clear exterior lit from within

Evocative of a futuristic spaceship, SelgasCano’s design of the Plasencia conference center and auditorium was selected in a 2005 competition. However, financing issues severely delayed the project’s completion to 2017. Now in operation, the building spans 7,500 square meters and includes an entrance lobby, a flexible 300-person secondary hall that can be split into three 100-person halls, the exhibition halls and the restaurant area.

clear circular door opening to a room

people partially seen through transparent orange wall

Set on a steep hillside straddling the border between urban development and the rural landscape, the conference center and auditorium was also designed to sit lightly on the land. Rather than fill in the site, the architects created a cantilevered shape to hover over the rocky terrain. They placed the entrance at the roadway, located 17 meters above the terrain, while inserting ramps and stairs that descend down to the various rooms.

Related: SelgasCano’s incredible glass office gives employees a bug’s eye view of the forest floor

auditorium with red seats and floors

people standing outside a room with transparent orange walls

“The building will be visible in the distance from an entire western perspective, from north to south,” the architects said. “It will be seen when passing by at high speed in a car, which is why we have planned it as a snapshot or a luminous form, acting as a sign for passengers by day and by night, playing at being a correspondence between sensation and reality, between the position it seems to be heading for and the position from where it will move.”

+ SelgasCano

Images by Iwan Baan via SelgasCano

raised walkway leading to translucent geometric building