Lupin, my cistern is stone with a nice smooth coat of cement on it. It's 7' deep, 7' wide, round or shaped like a bowl. It's also 10' away from my well so they weren't taking any chances with running out of water. I joke about putting leg irons down there and clawing the walls with red paint on my hands

Seriously though, I saw in a magazine where someone had put in a spiral staircase under a trap door, lined the walls with custom cabinetry and made a wine cellar out of theirs! Nice stuff...