Mammoth Cave National Park will offer free Mammoth Passage cave tours today through April 25 to commemorate National Parks Week.

The guided tours will depart from the park’s visitor center at 9 a.m., 10 a.m., 11 a.m., 12:15 p.m., 1:15 p.m., 2:45 p.m. and 4:30 p.m.

Visitors must pick up their free tickets at the visitor center ticket office prior to tour times.

Each tour lasts 1 hour and 15 minutes and covers a 3/4-mile stretch that enters the cave at the Historic Entrance and follows a route along Houchins Narroes, the Rotunda, the nitre mining artifacts, Audubon Avenue and Rafinesque Hall.