Khao Hin Son Royal Development Study Center

Khao Hin Son Royal Development Study Center sits on Highway 304 in Chachoengsao province, founded by King Bhumibol Adulyadej on 8 August 1979 as one of six royal development study centers set up around Thailand to research farming methods suited to each region’s terrain and climate. Here the focus is “New Theory” integrated agriculture — dividing land between rice paddy, mixed crops, fish ponds, and forestry so a small farm can sustain a household through drought or flood. Entry to the grounds is free, daily 08:30-16:30.

The demonstration plots cover reforested hillside, several reservoirs built for irrigation research, and rows of test crops — everything from vetiver grass planted for erosion control to fruit orchards and fish-farming ponds. Signposted pavilions explain what each plot is testing, aimed at the farmers who visit to take ideas home as much as at tourists. On the same grounds is the Khao Hin Son Botanic Garden, Thailand’s largest botanic garden, with over 3,000 plant species, marked trails, and an arboretum — worth combining with the study center in a single visit since they share the same access road.

Insider Tip: The center gets far more farmer study-tour groups than foreign tourists, so don’t expect a polished visitor center — it’s a working research station, and that’s the appeal for anyone curious about how the monarchy’s rural development projects actually function on the ground.

Staff run the site primarily for agricultural education rather than leisure visits, so signage leans technical (soil types, crop yields, water cycles) rather than scenic. Watch out: if you want a guided explanation of the New Theory farming model rather than just walking the plots yourself, call ahead (0 5324 8604 during office hours) to arrange it — turning up unannounced means self-guided grounds only.