You'll find the first treasure behind the big tent in the circus area.
This one is atop the dunking booth in the same area.
This one is pretty straightforward. Leap the gap with the Sabertooth costume, step on the switch, and slow time with the Thief costume to enter the Ancestor Door before it closes.
At the northeast corner of the village is an Ancestor Door. Deflect a fireball with the Samurai costume to get the treasure inside.
Cross the castle bridge to the moat. Immediately to the left is a target and a series of dummies. Use the Archer and Sabertooth costumes to cross the gaps and access the Ancestor Door on the other side.
On the opposite side of the bridge is a spot where you can fire an Archer costume's rope arrow. Cross over to snag another treasure.
A few paces east of the castle bridge is a lower platform with an Ancestor Door. Bust it open with the Jailbird costume's ball and chain to claim the treasure inside.
You'll find this on a balcony at the northern edge of town, just east of the previous treasure.
This one is for sir Galleth. In the northeastern part of the map is a tower only he can ascend. Scale it to find this treasure at the top.
On the eastern side of town is this hard-to-spot cellar. A treasure lies inside.
Here's another one for Sir Galleth. In the south-center of town is a tower only he can ascend using his Catapult Crash technique. Scale the tower to find the treasure at the top.
This one lies behind an Ancestor Door in the southeastern part of the map. Use the Archer costume's rope arrows to get there.