10 Images

Ice caves in northern Wisconsin are dazzling winter phenomena

Explorers drawn to ice show

Mother Nature has become a Chihuly-like sculptress in sea caves along Lake Superior in northern Wisconsin. Icicles hang by the thousands in caves at Apostle Islands National Lakeshore. In warmer weather, the caves would be accessible only by water, but during this consistently cold winter, they are accessible by frozen lakeshore. (Brian Peterson / Associated Press)

Delicate icicles form inside cave

Icicles assume fantastic shapes inside a cave at Apostle Islands National Lakeshore in northern Wisconsin. (Brian Peterson / Associated Press)

Ice caves forming in frigid winter

Small ice caves like this 4-foot high one pockmark the red cliffs abutting Lake Superior. (Mark Hoffman / MCT)

Ice caves explorer

This is the first time the ice caves in the Apostle Islands National Lakeshore have been accessible over the ice since 2009. (Mark Hoffman / MCT)

Winter hikers see rare ice formations

Bundled-up visitors are flocking to the caves at Apostle Islands National Lakeshore in northern Wisconsin, which have been transformed into ice sculptures in the arctic freeze. (Brian Peterson / AP)

Icicles form in cave

Icicles form in the frigid interior of a cave at Apostle Islands National Lakeshore in northern Wisconsin. (Brian Peterson / AP)

Hikers trek to ice caves

In this Feb. 2 photograph, crowds hike to the caves at Apostle Islands National Lakeshore. (Brian Peterson / Associated Press)

Posing for ice cave photos

Visitors snap photos inside an ice cave at Apostle Islands National Lakeshore in northern Wisconsin. (Brian Peterson / Associated Press)

Phogographer at work in ice cave

A visitor attempts to capture the wonder of a frozen cave at Apostle Islands National Lakeshore in northern Wisconsin. (Brian Peterson / Associated Press)

Ice cave icicles

Icicles resemble an art installation inside a cave at Apostle Islands National Lakeshore in northern Wisconsin. (Brian Peterson / AP)