The Apostle Islands ice caves on Lake Superior's south shore in Southern Wisconsin have reopened for the first time since 2015. The National Park Service (NPS) has announced that the caves are accessible due to favorable weather conditions, including extended periods of extreme cold and minimal wind, which have allowed Lake Superior to freeze sufficiently. The ice coverage must reach at least 90% for safe passage to the caves, a condition met this year. Historically, the caves have been open only 2% of the time from 2000 to 2023, with most openings occurring in 2004, 2008, 2009, and 2014. Visitors can expect a challenging hike of 2 to 6 miles round-trip on uneven ice, with no shelter or cell service available.