Alamagan

The Northern Marianas island of Alamagan is located 146 nautical miles (270 km) north from Saipan and is 11.12 km² (4.295 sq mi) in area. The island's volcano (Bandeera Peak) has a large caldera at the summit. The volcano last erupted around 870 AD, with an error bar of 100 years. It involved pyroclastic flows, and had a VEI of 4. Any claims of historical eruptions are inaccurate, though uncertain eruptions have occurred as late as 1887.