Visit the G-Cans
It's a huge underground tunnel built to allow rainwater to flow in the case of heavy rainfall.
Tokyo's other big market
You've heard about Tsukiji. Do you know about Ota Market?
They handle vegetables, fruits and flowers. And it's just as fun as Tsukiji, but without the long queues to get in.
Enter the National Diet Building
Visit the House of Councillors and walk the same hallway of Japanese politicians.
No reservations are necessary and the tours are held every weekday.
See the inside of Imperial Palace
Many of the locals aren't aware that you can actually see the inside of the Imperial Palace - and of course it's free!