If you want to play in the Apostle Island ice caves, you'll have to pay.

From now on, the National Park Service plans to charge a $5 fee to visitors ages 16 and older who want to visit the ice caves.

That is, if the weather gets cold enough to re-create last year's winter spectacle.

Last year, 138,000 visitors trekked across a frozen-solid Lake Superior to wonder at the glittering ice caves along the Wisconsin shore. The Park Service spent $450,000 dealing with the crowds and only charged a $3 parking fee that raised just $47,000 and was bypassed by many visitors who simply parked along Highway 13 or in temporary lots nearby.

Last winter was the first time in five years that conditions were cold enough to make the caves accessible. Images of the icy wonderland went viral, drawing record numbers of visitors. In a press release Thursday, the park service noted that "visitation of this magnitude may be the norm, rather than the exception."

The next time conditions are right, visitors can either pay for a $5-per-person day pass in the Meyers Road parking area or purchase a $10 annual park pass from the Apostle Island park headquarters in Bayfield.