Apostle Islands National Shoreline , Wisconsin ( CNN ) -- For thousands of years , waves on the largest of the Great Lakes have battered northwest Wisconsin , shaping the dramatic sandstone caves of the Apostle Islands National Lakeshore . But that punishment halted this winter when 93 % of Lake Superior froze , creating a spectacular icy landscape many locals say they have n't seen in a generation . It 's a serendipitous spinoff from the five Great Lakes being virtually frozen over this winter , a rare event that marks the arctic misery afflicting the Midwest . At one point , more than 90 % of the world 's largest surface freshwater system was frozen over , the National Oceanic and Atmospheric Administration said . That figure for the Great Lakes fell to 84 % as of Wednesday . The massive freeze , however , has created natural wonders . Bob Krumenaker , the National Park Service 's superintendent at Lakeshore , said there have been thousands of additional visitors flocking to ice caves . `` The caves form almost the same kind of features that you 'd find in an underground limestone cave -- the soda straws , the curtains , the stalactites -- but they 're all forming out of ice in just days and weeks instead of something that would form underground in limestone over hundreds of thousands of years , '' he said . This season has easily been the busiest in terms of visitors : In the past two months , more than 120,000 people have made the roughly three-mile round-trip trek by foot over a frozen Lake Superior to see the ice formations and caves that will melt away in just a few weeks . Debbie Stumpf was one of the intrepid visitors Wednesday . She likened the experience to `` walking into a hall of gods . '' `` How many chances do you have to lay on your back and look up at icicles ? '' she said . The journey to the caves is a big part of the experience . `` I like that we have to walk so far out to get here . We 've seen some really unique people out here , '' she said . Visitors have hailed from all over the world this winter , including China , Japan , Australia and Hungary , Krumenaker said . They all helped make this year the busiest in the history of the park , which received National Lakeshore status under the U.S. Department of the Interior in 1970 . CNN 's Michael Martinez contributed to this report .
The ice caves are spectacular this summer at Thousand Islands National Lakeshore . The freezing of the Great Lakes has created a natural wonder . More than 500 people walk three miles round - trip over a frozen Lake Superior . The caves are like ` ` walking into a hall of mirrors , '' visitor says .