Tokyo Architecture, Showa-Kan

Near the Kudanshita Station from Chiyoda-ku, Tokyo, I found one of the most unusual buildings I've seen in Japan. It looks like a huge archway clad in titanium panels, with no visible windows, creating the impression of a building from a dystopian movie...
But this architectonic design is actually fit for the purpose of this building: this is the National Showa Memorial Museum, also known as Showa-Kan 「昭和館」, a museum dedicated to commemorate the sufferings of the Japanese people during and after the World War II (the Showa period in the Japanese calendar).

Opened in 1999, Showa-Kan was designed by the famous architect Kiyonori Kikutake, founder of the Japanese Metabolist group (another member of this group was Kisho Kurokawa, the designer of the Nakagin Capsule Tower).