Near the center of the aboveground section of the Enclave, there is a cylindrical tower made of rough grey stone that is about 20 stories tall. It's about 150' in diameter at the base and somewhat narrower at the top, where there is an observation deck that can view most of the aboveground area. There are also numerous windows on all levels. This is the Enclave Watchtower, headquarters of the Enclave Watch. The Watchmaster, Harris Greymane, has his office on the 2nd floor.
The ground floor contains a main desk, staffed by several officers during the day and at least two at night. Citizens come here to report crimes or public safety issues, volunteer to join the Watch, or generally complain.
The tower contains some offices, plus ample storage space for Watch uniforms, weaponry, armor, and equipment. A fair amount of the interior space is devoted to a spiral staircase, with numerous landings providing access to windows and arrowslits. There is a large basement which is used for training of Watch officers.