UN BUEN POZO DE BAÑO

This is 500 tons of Colorado sandstone, some gravity and Thea Alvin floating 12 feet (4m) down at the bottom. It's a spiral staircase cistern designed and built by Thea to hold 10,000 gallons of water (about 38,000 litres) used to irrigate the gardens of a home in Boulder, Colorado, USA.