Samut Prakan was built as a frontier town to protect the approach to Bangkok upriver. Fortresses were built on both sides of the river as well as on an island opposite the city hall. Phi Sua Samut Fortress (เกาะป้อมผีเสื้อสมุทร) was initially built between 1819 and 1822. Defences were later strengthened by King Rama V when he bought three British made 6 inch guns in 1892. The only time they were fired in anger was against the French less than a year later. The island is now being turned into a tourist attraction. A bridge has been built at the Northern end and a concrete walkway along the Western side of the island. Although it seems to be finished already, it hasn’t been officially opened due to allegations of corruption and shoddy workmanship. However, local people have already started to visit.
Map showing location of Phi Sua Samut Fortress in Samut Prakan:
GPS Coordinates: 13.595567, 100.587794