Shonandaira is a large, flat, hilltop park between the city of Hiratsuka and the town of Oiso in Kanagawa Prefecture. It is easily accessible by car, although parking at the top is limited. There is also a moderate level trail starting in Oiso that leads to the top.
It is a popular weekend spot for couples and families because of its large open space. It's a great area for a picnic or a romantic night view.