https://tourillinois.org/things-to-do/listing/cave-in-rock-state-park/
Cave-in-Rock State Park is made up of its namesake cavern and acres of forest along the Ohio River.
cave in rockstate parkenjoyillinois
https://www.livescience.com/archaeology/9000-year-old-rock-art-of-people-swimming-in-whats-now-the-arid-sahara
This series of paintings, found inside a cave in the Sahara, shows a pair of swimmers.
cave of swimmersyear oldrock art