Many people consider Marengo Cave, in northeastern Crawford County
, one of the most beautiful caves in the United States. In 1883 children noticed an opening near the bottom of a sinkhole. Inside, they found a large, subterranean room now known as the Grand Entrance Hall. Lacking some of the spectacular features of Wyandotte Cave, Marengo Cave displays an abundance of stalactites, stalagmites and other dripstone formations. Among the many features are Crystal Palace, Rock of Ages, and Pillared Palace.