Residence of the Emperor
None (but surrounded by base defenses and the Imperial forces)
The Imperial Palace is Emperor Yoshiro's private residence on Mt. Fuji, Japan. It is part of a sprawling complex (which also housed the Imperial Geishas) and is heavily guarded by regiments of only the most loyal Imperial troops, and Japan's most advanced and elite mechanized forces; just in case some filthy barbarians manage to sneak in.
War of the Three Powers
During the Allied assault on Tokyo, Yuriko Omega was found unconscious underneath the ruins of the Imperial Palace. She was subsequently taken into Allied custody, and transferred to Camp Dakota, a detention facility in Guam.
|The following is based on the Soviet campaign of Red Alert 3 and contradicts canon sources.|
During Operation: To Tame a Living God, the Palace grounds was infiltrated by a conscript and a war bear in a daring yet foolhardy attempt to assassinate Yoshiro. When the Emperor survived, thanks to the decoy placed in the Garden, the Soviets brought in heavier equipment - such as Apocalypse Tanks - and leveled the Palace after having done away with the three Imperial Commanders, and the elite garrison defending it.
Emperor Yoshiro himself emerged from the ruins of the Palace and made his last stand here in a special Red King Oni before being surrounded and slain by Soviet forces.
The Emperor's Palace is actually based off of the real world Fujimi Yagura watchtower located on the grounds of the Tokyo Imperial Palace