Germany’s Heidelberg Castle is home to a famously enormous wine barrel, capable of holding 57,853 U.S. gallons. This is actually the most recent of four enormous wine barrels that the castle has housed, the first built in 1591. Unfortunately it’s empty — today it serves mostly as a tourist attraction and a foundation for the fanciful dance floor above it.

“Everybody has heard of the great Heidelberg Tun,” wrote Mark Twain in A Tramp Abroad, “and most people have seen it, no doubt. It is a wine-cask as big as a cottage, and some traditions say it holds eighteen thousand bottles, and other traditions say it holds eighteen hundred million barrels. I think it likely that one of these statements is a mistake, and the other is a lie. However, the mere matter of capacity is a thing of no sort of consequence, since the cask is empty, and indeed has always been empty, history says. An empty cask the size of a cathedral could excite but little emotion in me.”