Wongwian Yai, also spelled "Wong Wian Yai" or "Wongwien Yai", is a large roundabout in Thonburi, on the west bank of the Chao Phraya River in Bangkok, Thailand, where the statue of King Taksin is situated.

Khlong San is one of the 50 districts (khet) of Bangkok, Thailand. On the west bank of Chao Phraya River, its neighboring districts across the river are Phra Nakhon, Samphanthawong, Bang Rak, Sathon, and Bang Kho Laem. On the west side of the river, the only land neighbor is Thon Buri district.