The Imperial Enclosure is a citadel-within-a-citadel, housing the emperor’s residence, temples and palaces and the main buildings of state within 6m-high, 2.5km-long walls. What’s left is only a fraction of the original – the enclosure was badly bombed during the French and American wars, and only 20 of its 148 buildings survived. This is a fascinating site easily worth half a day, but poor signage can make navigation a bit difficult. Restoration and reconstruction is ongoing.
Expect a lot of broken masonry, rubble, cracked tiling and weeds as you work your way around. Nevertheless it's enjoyable as a leisurely stroll and some of the less-visited areas are highly atmospheric. There are little cafes and souvenir stands dotted around.
It's best to approach the sights starting from Ngo Mon Gate and moving anticlockwise around the enclosure