Nepal Warzone
Nepal Warzone is a section of the Urban Warfare single player mission. In co-op arena, Nepal Warzone plays exactly like the single player mission, requiring players to shoot their way through the plaza to reach the treasure. This mission is very linear, with most shootouts taking place in small alleys and corridors. Very little platforming is involved, with the bulk of the mission relying on shoot and cover.
The Sanctuary
The Sanctuary is a section of the Monastery single player mission. Much larger than Nepal, the Sanctuary provides more room for long-ranged firefights and platforming. Enemies come from multiple locations simultaneously, generally forcing players onto the rooftops until the first checkpoint has been reached. The final section of the map takes place in a tower where close-range combat is prevalent.
The Village
The Village is a section of the Siege and Cat and Mouse single player missions. The combat is varied, with enemies attacking you up close as you try to clear buildings, and from a distance as you make progress up the mountain. Unlike the aforementioned missions, the Village features enemy helicopters and tanks that must be defeated to complete the mission.
Highrise and Museum
Available only in the premium Siege Expansion Pack DLC, Highrise and Museum are two large, open-ended maps that offer many hiding places for your team and many areas for enemies to attack from. Highrise is a section of the Hotel Shangri-la single player mission, and includes many of its ledges and climbable locations. Museum is a section of the Istanbul Palace Museum single player mission, which takes place during dusk and offers many rooftops to camp on.