Fort Phra Sumen: I walked from Khao San Road towards the nearest Phra Arthit Pier on the river. Near the Phra Arthit Pier, I came across an interesting fort known as Phra Sumen Fort. It is one of the only two remaining fort of old Bangkok and considered as the last citadel on the Chao Phraya. This fort was built by King Rama I in 1783 for the defense of his new capital,Bangkok. This fort looks impressive with its white painted structure with the old canon still looking from one of the peep hole.