It was King Prasat Thong who build Bang Pa-In, also known as the summer palace.
The king started the constructions of Bang Pa-In Royal Palace in 1632. But in the late 18 century and the beginning of the 19th centuries, it was almost forgotten and fell into disrepair and was almost completely overgrown until King Mongkut began to restore the palace in the mid-19th century.
Most of today’s buildings were built by King Chulalongkorn (Rama IV) between 1872 and 1889.
Today the Bang Pa-In open to visitors, as the palace is seldom used by the royal family, and when used, it is mostly for state occasions and not as a summer palace.
The palace is located 60 kilometers north of Bangkok along the banks of the Chaopraya River. A very nice and comfortable way to get there is by one of the many luxury cruises available from the hotels along the river, there is also an express boat service on Sundays from Prachan pier.
Bang Pa-In Royal Palace is open from 8:30 am to 5:00 pm, though the ticket office closes at 3:30 pm.
It is really worth a visit.