Mainland Sea Caves, Apostle Islands National Lakeshore
Icicles line sandstone walls of the mainland sea caves at Apostle Islands National Lakeshore, Lake Superior.
The mainland sea caves are sandstone formations along Lake Superior within Apostle Islands National Lakeshore in Wisconsin. In winter, when the lake ice is stable, visitors can walk onto the ice to view the caves' frozen icicle formations from the shoreline. The National Park Service manages access to the caves and issues advisories based on ice conditions each season.
Photo taken in February 2014.
