A 145-foot high under­ground water­fall that is illu­mi­nat­ed to cre­ate this love­ly pur­plish hue. It is locat­ed with­in Look­out Moun­tain near Ten­nessee. They have exist­ed for mil­lions of years. Ruby Falls Cave fea­tures promi­nent cave for­ma­tions like sta­lac­tites and sta­lag­mites, columns, drap­ery, and flow stone. The caves were opened to the pub­lic only recent­ly, so make sure you don’t miss out on a trip to this des­ti­na­tion.