After 20 years of planning, construction has finally started on the €9.5 million “Musuem unter Tage” in the German city of Bochum, Der Westen reports.

The entire 1,900-square-meter space is being built seven meters (23 feet) under Bochum’s Weitmarer Schlosspark. From the surface, the museum will be recognizable only by three entrances and one emergency exit. “A staircase will lead to an underground hall from where visitors will be able to discover the artworks in three separate rooms,” Andreas Schindler of the Bochum-based architectural firm Vervoorts & Schindler explains.

The Museum unter Tage was originally conceived in 1991 by the gallerist Alexander von Berswordt-Wallrabe. A descendent of the aristocratic family that once owned the land, he founded the Situation Kunst Museum in honor of Dr. Max Imdahl, founding professor of the Art History Institute at the Ruhr University, Bochum.

In 2006, the construction of the first space was completed. In 2010, the addition of a further building, a glass cube built within the ruins of the estate’s main structure was added. The underground Museum unter Tage is the third and final phase of the complete Situation Kunst Museum as envisioned by its founder.

The new space will primarily show landscape painting from the 17th century to today. Some works will be relocated to the underground facility from other parts of the park, including paintings by the Dutch artist Joos de Momper. Curator Maria Schulte also revealed that there “Will also be video and sound art, as well as special exhibitions.”

The museum is scheduled to open in November 2015.