The Stock im Eisen

Step up to the glass on the corner. That dark trunk, just over two metres tall, is covered in thousands of nails. It is the Stock im Eisen, the "stick in iron", and one of the oldest objects in the city.

1What science says

In 1975 its rings were studied: it is a spruce that began growing around 1400 and was felled around 1440. Some nails are partly overgrown by the wood, so they were driven in while the tree was still alive. A document of 1533 already mentions it, and in 1575 the owner of the house, probably one Hans Buettinger, renewed the iron band with its padlock. It is a dummy lock: it has no mechanism to open.

2What legend says

The best-known version tells of a locksmith's apprentice who sold his soul to the devil in exchange for forging a lock that could never be opened. Another claims the devil himself bound the trunk in iron. From the 18th century, journeymen craftsmen arriving in Vienna hammered in a nail here for luck during their stay, a custom that made the trunk famous across Europe.

No one knows why people first started nailing it. The most accepted theory is a votive offering, like tossing a coin into a fountain today.

In 1944 a caretaker hid it to save it from the war, and it returned to its place in 1951.

3What to look for

• The iron band with the padlock and the engraved initials.
• The density of the nails: hardly any wood is left showing.
• The cathedral reflected in the glass front of the Haas-Haus opposite.