It’s always good to see some historical landmarks still remaining in Bangkok. This structure in front of Central Embassy used to be one of six boundary markers on the land owned by Nai Lert. This is the information about it from the plaque:
In 1909, Phraya Bhakdinoraseth (Lert Sreshthaputra) bought a vast plot of land near Saen Saep canal. The low lying land, full of tall grass and reeds, was developed, next to the roads which Nai Lert named Ploenchit, Chidlom and Somkid, and turned this land into a huge park where he built a villa, known today as the Nai Lert Park Heritage Home. Nai Lert, the visionary, designed unique boundary markers. The six two metre tall markers, built to imitate ancient cannons with their muzzles pointing to the ground, were placed along the border line to prevent future boundary dispute and to facilitate the boundary survey. Many years later, the markers were dismantled, with only one left at the Wittayu-Ploenchit intersection. This remaining marker is considered to be one of the historical monuments of Pathumwan District in Bangkok.