With a perpetual three-month waiting list, this is surely one of Berlin’s most treasured private art collections.

When Christian Boros acquired this Nazi-era bunker in 2003, he gained not only a 3,000-square-meter space for his modern art collection but also a piece of Berlin’s colorful history. Built in 1942 to protect passengers of nearby Friedrichstraße Station from aerial bombardment, the concrete structure found a sweeter postwar use storing tropical fruit for East Berliners, who dubbed it the “Banana Bunker.” It then had a brief stint as a hardcore techno and fetish club, until city authorities shut it down in 1996.

Boros converted the bunker to exhibit his extensive collection featuring artists such as Olafur Eliasson, Damien Hirst, Terence Koh and more. In 2008, following five years of difficult renovations—reinforced concrete walls had to be cut out with diamond-tipped drills and broken up before being removed by hand—Boros and his wife took up residence in the penthouse and opened the bunker’s heavy steel doors to the public.