have visited Grinpa 1 year ago.
It's large in space but not many things to see. actually I visited the whole park by using half day only. However, I had to spend 1 day for this 'cos there are only 2 Grinpa shuttle bus travelling between 御殿場 and Grinpa every day. (one is in the morning around 9am from 御殿場 and the other one is at around 4pm from Grinpa. Hope this helps.
森林家族 (Grinpa)
裾野市須山字藤原2427
Open Hour: 9:30am-4pm
入場1日費用: 3200yen
小田急旅行中心 (Odakyu Sightseeing Service Centre)
新宿站西口1樓中央大堂 (8am-6pm)