Štola v Zoo, Mining adit in Prague Zoo, Czech Republic

Štola v Zoo is a 19th-century adit beneath the Skály natural monument in Prague-Troja, dug into the rock inside the zoo grounds. Its entrance section now holds an exhibition on the shelter installed there during the Second World War, with period sound effects. The passage runs only a few dozen metres; a second, buried lower level may exist.

Mining operations began in the 1800s to extract minerals from beneath this area before the work eventually ceased. During World War II, people sheltered inside these tunnels when seeking refuge from aerial bombing.

The adit's name, Štola v Zoo, simply means "adit in the zoo". Since 4 May 2014 its front section has held an exhibit on the wartime air-raid shelter, with period sound effects. A story is told of Mrs Trubková, wife of a circus animal tamer, who ran with her children into the shelter whenever the siren sounded.

The tunnel is open to zoo visitors and can be explored as part of your zoo visit. Wear appropriate footwear since the ground is uneven and the space can be damp.

Around 1880 the Prague natural-history dealer Václav Frič took mineral samples from crusts on the adit walls, formed by sulphates precipitating as pyrite decayed. In 1881 Josef Klvaňa of the Museum of the Kingdom of Bohemia identified epsomite, halotrichite and keramohalite, some of them first finds in Bohemia, and named a previously unknown mineral paracoquimbit after the Troja adit.