In between Lake Saroma and The Sea of Okhotsk, there is a thin strip of land that you can cross on a bicycle. The official name of this place is Wakka Nature Center. To cross this thin strip of land, you can rent a bicycle here for 500 yen. The place has many unique plants that can only be found here, and I recall they sold some really good ice cream at the end of the trail. Wonderful place to spend a Sunday afternoon.
The Japanese name for the place is ワッカ原生花園 (wakka genseikaen).