Country/territory: Japan
Central coordinates (latitude / longitude): 38°43'00"N (38.7167°) / 141°07'00"E (141.1167°)
Area (reported): 1,800 hectares / 18.00 km² / 4,448 acres / 6.95 square miles
Area (GIS-derived): 1,992 hectares / 19.92 km² / 4,922 acres / 7.69 square miles
Altitude: 0–40 m (0–131 ft)