Generally, a Bang Pa In visit is combined with a visit to Ayutthaya for a day. Bang Pa In is a Summer Palace and even though its history dates back several centuries, most of the current buildings date from the end of the 19th century.
If I choose to visit the site on foot, it can be done in a golf cart for those of us who are lazy, since the palace is relatively large. So I discovered a mixture of several styles of buildings that seemed a little confusing to me: sometimes we came upon a completely wooden European-style building, and further along a sort of lighthouse that serves as a viewpoint on the site, which is very well maintained, and even further away, there's a building in the more pure Chinese-style.
For an unusual travel experience, go behind the palace. In order to go see the Wat Niwet Thamaprawattemple, you have to take a little cable car, which brings you to the island in the middle of the Chao Phraya River. Not only is this experience unique, but the temple itself has a surprise. Upon arriving, first we see a church, yet it's beautiful and a Buddhist temple, built as such by request of King Rama V.