Teamlab Borderless
As the end of our time in Tokyo approached, we had to rapidly run down the list of things we had wanted to do before leaving. (Spoiler: we did not do half of them.) One of those things was to visit the "digital art museum" Teamlab Borderless.
It's located in Roppongi. Once upon a time Roppongi was a very seedy district, but developers have moved in and largely turned it into a high-end mixed Retail-Office-Residential area. It is also a maze.