The Soudan Underground Mine is a historic iron ore mine located in Minnesota, USA. It operated from 1882 until 1962 and is known for its rich deposits of iron ore, which played a significant role in the region's economy. Today, it is preserved as a state park and offers guided tours to educate visitors about mining history and geology. The mine extends over 2,300 feet underground and features a unique underground lake. It is part of the Soudan Underground Mine State Park, which also includes hiking trails and picnic areas, making it a popular destination for outdoor enthusiasts and history buffs alike.