Tokyo's historic heart, Asakusa is home to the impressive Senso-ji temple, among many other cultural sites. The whole place feels a little bit like Disneyland, with everything done up to preserve an overall historic feel. Asakusa is the place in Tokyo to stock up on all those traditional trinkets and crafts you'll want to bring home. A day in Asakusa should be spent perusing street stalls while nibbling on traditional snacks made fresh in front of you.
A leisurely day could easily be spent in Asakusa, strolling and browsing, although the more active will probably want to just make it a half day. Before leaving, though, grab your fortune (available in English) from Senso-ji; it's said to give the most accurate predictions around.
Here you'll find the Akasuka Shrine - possibly the most famous temple in Japan. Asakusa is also the location of Tokyo's largest hanabi (fireworks) festival, so if you're here in the summer – and don't mind pushing your way through the throngs – it's a perfect opportunity to don a yukata (traditional summer kimono) and experience Japan as it used to be.