The Imperial Palace, home of the Imperial family, is the heart and soul of Tokyo. Built on the very spot where Edo Castle used to stand during the days of the Tokugawa shogunate, it became the Imperial home upon its completion in 1888 and is now the residence of Emperor Akihito, 125th emperor of Japan. Destroyed during air raids in 1945, the palace was rebuilt in 1968 using the principles of traditional Japanese architecture. But don't expect to get a good look at it; most of the palace grounds' 114 hectares (282 acres) are off-limits to the public, with the exception of 2 days a year when the royal family makes an appearance before the throngs: January 2 and December 23 (the emperor's birthday). Or, you can visit Imperial grounds on free guided tours Monday through Friday at 10am and 1:30pm (1:30pm tour not available July 21-Aug 31), but you must register at least 1 day in advance (reservations are accepted up to 1 month in advance) by calling tel. 03/3213-1111 and then stopping by the Imperial Household Agency (located at the Sakashita-mon Gate, on the east side of the palace grounds) to show your passport number and provide nationality, name, age, gender, and home address. Easier is to book through the Internet at http://sankan.kunaicho.go.jp/English/index.html at least 4 days before the tour. Tours, conducted in Japanese only but with English-language audioguides available, last about 75 minutes and lead past official buildings, the inner moat and historic fortifications, and Nijubashi Bridge. I recommend this tour only if you have time to spare and have already seen Tokyo's other top attractions.
Otherwise, you'll have to console yourself with a camera shot of the palace from the southeast side of Nijubashi Bridge, where the moat and the palace turrets show above the trees. Most Japanese tourists make brief stops here to pay their respects. The wide moat, lined with cherry trees, is especially beautiful in the spring. You might even want to spend an hour strolling the 4.8km (3 miles) around the palace and moat. But the most important thing to do in the palace's vicinity is visit its Higashi Gyoen (East Garden), where you'll find what's left of the central keep of old Edo Castle, the stone foundation.