Hrebenom Nizkych Tatier

The Hrebenom Nizkych Tatier geocache (GC7DY00), "along the ridge of the Low Tatras", takes four to five days of walking. Placed in October 2017 by the Czech geocacher Čtyřhranka, it follows the crest line of the Low Tatras over some hundred kilometres, most of it between 1,500 and 1,800 metres.

The red-blazed trail it borrows has a name: Cesta hrdinov SNP, the road of the heroes of the Slovak National Uprising, doubling here as European path E8. The route never leaves the Low Tatras National Park, where camping out remains forbidden outside the designated spots. The brown bear is its emblem; on the ridge itself you will rather meet chamois, brought back from the High Tatras in 1969, and marmots.

Seventeen clues, from A to Q, mark out the way, each one laid in duplicate - an engraved aluminium plate and a virtual question - before the formulas give up the final coordinates. The box holds postcards, to be sent to the owner whose address is in the logbook. Voted geocache of the week in March 2020.