We visited Planting Fields Arboretum, which is a very nice state park that used to be a private estate owned by William Coe and his wife. (Coe made serious money in maritime insurance; his wife was the heiress of Standard Oil, which of course made her much richer than he.) There are a number of buildings worth visiting on the estate. Coe Hall is a beautiful old mansion that at one point was used by SUNY Stony Brook before their campus was built. There are a number of old greenhouses that have some nice collections of plants. All in all, worth visiting.