Sanam Chai is the name given to Bangkok portion of the canal, which is known as Mahachai in Samut Sakhon.

For the Khlong Dan part, it is believed that it is a natural canal that has existed since the Ayutthaya period.

The digging was completed in the year 1721 during the King Sanphet IX's reign, with Dutch experts in charge of the excavation.

Covering a total area of 76.42 km2 (29.50 mi2) of Bangkok and provinces of Samut Sakhon with Nakhon Pathom.

[1] Fort Wichien Chodok, a fortress built in the King Nangklao (Rama III)'s reign at the mouth of the canal where it confluence with the Tha Chin river to prevent the invasion of Annamese from the case of Anuwong's rebellion.