OK, are you wondering what the heck a cistern is? Pardon me for a moment… (I’m back)… here it is straight from Noah Webster himself: Cistern – Is a waterproof receptacle for holding liquids, usually water. Cisterns can be above or below ground and were commonly used in Key West to capture & store rain water since fresh water was scarce.
Seen here is an awesome photo showing how the rain is captured from the roof into copper gutters traveling downward to its final destination. This above ground cistern survives as part of the Lignumvitae Key State Park’s only home on the entire key.
Though not free, you can find a catamaran tour boat company to take you to Lignumvitae Key at Robbie’s Marina at Mile Marker 77.5 on US-1 bayside.