Map showing Bangkok's forts and city walls.
The Rattanakosin forts are:

Phra Sumen
Yukhonthon
Maha Prap
Mahakan
Mu Thaluang
Suea Thayan
Maha Chai
Chak Phet
Phisuea
Maha Roek
Maha Yak
Phra Chan
Phra Athit
IsinthonThe 1852 forts are:

Pong Patchamit
Pit Patchanuek
Huek Hiam Han
Phlan Phairi Rap
Prap Sattru Phai
Thamlai Porapak
Hak Kamlang Datsakon
Maha Nakhon Raksa
Own work
Paul_012