This one was a bit of a surprise. When I originally looked up UNESCO sites in Japan, this didn't come up, I think as there are multiple sites from Le Corbusier worldwide.

We went to Ueno Park (which has an incredible 6 museums and a zoo in the ground, so is well worth a visit), to find the Museum of Western Art, by Le Corbusier, and it was free to enter the grounds and the gallery itself.

I don't have a great understanding of architecture, but I didn't think it was that impressive a building, thouh it was still worth going to to see the works by Rodin, Picasso and Monet inside.