Just south of the hideout is a series of islands you can traverse using the Archer costume's rope arrows. On the third island is an Ancestor Door guarding the first treasure. The starting point is marked as (1) on the map.
In the southern portion of the map is an Ancestor Door guarded by a laser floor. You can reach it with the Jailbird costume's ball and chain to claim the treasure. You'll also need to use the Samurai costume to deflect a fireball and open the door.
You'll find this one at street level in the southeastern part of the city.
This one's on a rooftop in the south-central part of the city.
Along the wall in the northeastern part of the city are some decorative monkey faces. Atop one rests a treasure, which you can reach via the springy flagpoles nearby.
This one is atop a crate on the eastern side of the map, just on the other side of the river.
In the northeastern section of the map, there is an opening in the wall. Head there and leap the gap with the Sabertooth costume. The Ancestor Door on the other side holds another treasure.
You'll find this one in a hallway north of the village. You'll recognize it as a location visited during a story mission.
This treasure sits atop the tall tower in the northern part of the city. You'll have to climb a snake pole to get there, so use Salim's Cobra Climb or the Thief costume's Slow Time ability to reach the top safely.
This treasure hides behind an archway in the northern part of the city.
You'll find this one behind another Ancestor Door, found on a peninsula adjacent to the palace. In the northwestern part of the map is a spot to fire a rope arrow with the Archer costume - marked by (11) on the map. Once across, hop on the switch and use the Thief costume to slow time and get inside before the door shuts.
Head to the extreme north of the map - behind the palace. Back here is a series of cages and laser floors leading to one last Ancestor Door. Use the Jailbird and Sabertooth costumes to head through the obstacles and claim the game's final treasure in the door beyond.