Yamanashi Fuehukigawa Fruit Park, Yamanashi

A free park based in a hillside orchard. Amazing indoor and outdoor playgrounds cater for kids. If you have a dog they are allowed at most places and there is a dedicated dog run. There is a barbecue restaurant, a wine bar and other restaurants, too. The view is breathtaking so much a Canadian friend has remarked that this was the most beautiful place he had ever been to.

If you live in Tokyo and have access to a car; owned, rented or borrowed, this is a great place to take your family out to. For the youngest ones there's tones of playgrounds including a massive water ground; which is designed for splashing (NOT swimming). Plenty of restaurants and things to do for the more older members who can lay on the ground for a picnic or have a coffee at the terrace restaurant and enjoy the view. You have an Onzen an a great hotel inside the premise too. The facilities are in superb condition and there are no entry fees.