The island is officially part of the borough of Algonquin and is situated on the Humboldt River between Algonquin and Broker. Unlike Charge Island to the north, Colony Island has a residential area and access to public transport, presumably due to its proximity and direct connection with Algonquin.
The Algonquin Bridge passes over the northern portion of the island, serving as an unofficial demarcation between the residential apartments from the south to the center, and the cemetery at the northern end featured in Undertaker depending on player choice. An industrial park, used in the mission Waste Not Want Knots, spans almost the entire north-eastern perimeter of the island, and a waterfront promenade runs along the western face, offering great views of the Algonquin skyline to the west. The southern end of the island is taken up by an abandoned hospital, featured in the mission The Snow Storm. A lighthouse is also situated on the northern tip of the island, accessible through the cemetery.
In GTA Chinatown Wars, Colony Island is modified to appear bisected by the Algonquin Bridge. As a result, only the southern half of the island is accessible from Algonquin, while the northern half containing the cemetery and lighthouse (where HoboTron takes place) is only reachable via boat.
Colony Island is analogous to New York City's Roosevelt Island. Both islands are located in the center of a major river separating two boroughs of the city; the Algonquin Bridge, like the Queensboro Bridge, passes over the island, and Colony Island's abandoned hospital is akin to the abandoned Smallpox Hospital on Roosevelt Island.
The Liberty Transport Authority operates a tram service between Lancet, Algonquin and the island, a replication of the Roosevelt Island Tramway. The tram station is located on President Street, partially overlapped by the southern side of the Algonquin Bridge.
Colony Island is also accessible via Leaper's Bridge, the only road link in and out of the island.
Colony is among the best locations for Team Deathmatch, as its size is not too big for 4 player matches, but not too small for 16 player matches. Also, trapping the enemy team in the cemetery on the northernmost part of the island allows for long killing streaks, especially if one's team has superior firepower.