Japan's Imperial Palace is an appropriate place to start the city's laundry list of interesting sights, as it is – geographically, at least – the centre of Tokyo. The leafy grounds occupy the site of the original Edo-jō, the Tokugawa shōgunate's castle when they ruled the land. In its heyday the castle was the largest in the world, though little remains of it today apart from the moat and walls. The present palace, completed in 1968, replaced the one built in 1888, which was destroyed during WWII.

As it's the home of Japan's emperor and imperial family, the palace itself is closed to the public for all but two days of the year, 2 January and 23 December (the Emperor's birthday). It is possible, however, to take a tour of the imperial grounds, but you must book ahead through the Imperial Household Agency's website. Reserve well in advance – slots become available on the first day of each month. Tours run twice daily from Monday to Friday (10am and 1.30pm), but on weekends, public holidays and afternoons from late July through to the end of August.

The main park of the palace grounds is the Imperial Palace East Garden, which is open to the public without reservations. You must take a token upon arrival and return it at the end of your visit.