Khlong Maha Nak is about 1.3 km (0.8 miles) in lengh. Created in 1783, it is one of the oldest existing canals in Bangkok. The canal is said to have been named after a monk whose name is Maha Nak. The monk was credited with having initiate the canal project.
Khlong Maha Nak on Google Street View
Khlong Maha Nak as seen from Saphan Naris Damrat (Feb 2018)