Historic Forts and City Walls in Bangkok
A visual guide from the Bangkok travel guide — see all posters in Visual Guides.
Bangkok once had fourteen forts stitched into a brick wall around its royal island. Two survive. Phra Sumen, octagonal and whitewashed, stands where Khlong Rop Krung meets the Chao Phraya, and the park below it is where Banglamphu comes to sit on the grass at dusk while barge trains slide past. The rest of the defensive ring was pulled down as the city outgrew it in the nineteenth century, leaving fragments of wall, two forts, and a far larger coastal battery an hour downriver at the estuary.
What survives
Phra Sumen Fort, built in the 1780s, anchors Santichaiprakarn Park on Phra Athit Road, a short walk from Khao San and free to wander at ground level. Mahakan Fort sits at the other end of the old canal near the Golden Mount, with a restored stretch of city wall running along Mahachai Road beside it; the surrounding community was cleared and the site now functions as a public park. Wichai Prasit Fort in Thonburi predates the capital by more than a century but lies inside a naval base and is not generally open to visitors.
Downriver at Paknam
For actual artillery, Phra Chulachomklao Fort at the river mouth in Samut Prakan is the better visit: sunken Armstrong gun emplacements from the 1890s, built for the confrontation with French warships, plus the retired HTMS Maeklong moored alongside and open to walk through. It sits roughly an hour from central Bangkok — BTS to Kheha at the end of the Sukhumvit line, then a taxi for the final stretch out to the river mouth. Allow a couple of hours, aim for late afternoon when the light comes off the estuary, and expect very little shade anywhere on the gun deck.