The Hranice Abyss – the deepest in the world

At first glance nothing special, at second glance something unique. There are plenty of abysses around the world, but the one in Hranice rules them all.

With a total measured depth of 519.5 metres, the Hranice Abyss is the deepest chasm in the Czech Republic. At the same time, its record water depth of 450 metres makes it the deepest flooded pit cave in the world. The bottom has not yet been reached.

An unusual karst process formed the unique chasm from the bottom up.
In the case of the Hranice Abyss, the karst agent is not water, but a lukewarm carbonic mineral water, heavily gassed with carbon dioxide. The aggressive acidulous water emerging from deep cracks ate away the limestone mass from below and created a cavity that caused the thin ceiling to collapse, opening the hollow to the surface.

The first written mention of the abyss dates from 1580, and it is also the oldest Moravian karst phenomenon recorded by John Amos Comenius in a map of Moravia.

An installed viewing platform allows you to see into the 69.5-metre-deep mouth of the abyss, providing an extraordinary view of its apparent bottom, which forms a green lake. But the abyss continues with an enormous flooded cavern that is considerably deeper.

Hranice abyss is situated in the Hůrka u Hranic National Nature Reserve. It is accessible on foot from Teplice nad Bečvou railway station, where you will also find a visitor centre. Its interactive exhibition includes, among other things, a cross-section of the Hranice Abyss and the Hranice Karst. You can also reach the site on foot by following the red signposted hiking trail from the caravan park in Hranice.

The Hranice Abyss is open to the public all year round, however it is not wheelchair accessible.