I visited this place in combination with a trip to the Nakhon Pathom Stupa. I loved this place, peaceful and so different from busy and crowed Bangkok.
We were the only foreign tourists here. The park gives a good view of the life of King Rama VI and some of his relatives and their will to bring Siam to the modern times, but with the ability to keep the overseas powers at bay.
The grounds are well maintained and you can hire a golfcart if you dont' feel walking. Park is huge...