The Clocktower is a two-building industrial complex in Grand Theft Auto IV.
Located in BOABO, Broker, and fronting the Humboldt River, the building can easily be spotted immediately south of the Algonquin Bridge by both its large rooftop CLOCKTOWER sign and functional digital clock synchronized to the in-game time. This meant the building is also visible to the right as the player drives across the bridge from Algonquin to Broker. Otherwise, the building is of little use in any part of the game, other than providing another means by which the player can check the in-game time.
At night, the large CLOCKTOWER sign on the roof lights up with red neon lights, however the "L" is slightly dimmer than the rest of the letters, resulting in the sign appearing to spell out "Cocktower". This is an obscene easter egg left in the game by Rockstar.
The entire complex, including the sign, bears resemblance to 25 Columbia Heights (known for a similarly designed "Watchtower" sign) in Brooklyn, New York City; in real-life, the building serves as a base of operation for the Watchtower Bible and Tract Society, an organization under Jehovah's Witnesses. The Clocktower building's in-game design, however, is scaled down and less modernized than its real-life counterpart. The orientation of the Clocktower's main building is also altered to face north when the Watchtower's faces west in real life.
The most curious thing is, that in the game is written a sign "for lease" and a few years after the GTA release, the Watchtower building has been sold in real life to bring more money inside the cult.