CUSTER, S.D. (AP) — One of the longest caves in the world is getting a bigger visitor center.

Work began Monday on a $671,000 expansion project for the visitor center at Jewel Cave in western South Dakota. Acting Superintendent Donald Hart says the project will make it easier for visitors to enter and exit the cave, and also provide more space for people waiting for a tour.

The project is scheduled to be completed in February. The center will remain open for regular hours during construction, and the cave tour schedule won't be impacted.

The National Park Service maintains Jewel Cave National Monument, 13 miles west of Custer. The cave has more than 177 miles of mapped and surveyed passages and is home to nine bat species, including the rare Townsend's big-eared bat.

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