Crystal clear waters, rugged caves and underwater caverns are just a taste of what Bruce Peninsula National park has to offer.
Peppersauce Cave in southern Arizona is relatively well known but not a tourist attraction. It's in a wilderness area on the north side of Mt. Lemon in the Santa Catalina mountains north of Tucson.
My spelunking experience involved crawling on hands and knees through underground tunnels. That's much different from visiting caverns where you can stand up.