Kenzo Tange's domineering Tokyo Metropolitan Government Building is worth visiting purely to have a good look at its spectacular edifice, but it's also home to a pair of free observation decks that have become a popular stop on many tourist itineraries. For good reason, too: unlike other contenders like Roppongi Hills's Tokyo City View and Tokyo Skytree, the TMG's observatories are completely free of charge. Particularly popular at sunset, when clear days afford good views of Mt Fuji, the observation decks also serve refreshments.
*Note that the North Observation Deck is currently closed.