Wat Huay Kaeo is especially famous and interesting for its Khmer-type chedi planted in the middle of a pond.
There's a green and white jade statue of Buddha inside the temple.
The place is also very beautiful from a drone point of view because when you get closer to the top of the chedi, there are 30-50 birds flying around from their nest. Quite magical sight.
It's about 30 minutes north of Lopburi, so it can make a nice stop if you drive north from Bangkok.