Caves With The Deepest Drop

A vertical drop or shaft is a place in a cave where the caver has to abseil. He needs a rope which is long enough, and so it helps to know the depth of the shaft. Going down the pit means a very long abseil to the bottom. A lot of energy transformed into heat, a problem for rope and abseil equipment. Also it is necessary to climb up the shaft along the rope afterwards using a method called single rope technique (SRT).

We made two different list of shafts, one is about the deepest underground drops, one about daylight shafts. Underground drops are completely underground, both ends, the lower and the upper, are inside a cave. A daylight shafts starts at the surface, which means the daylight shines into the shaft, hence the name. On the other hand there are pitches and single drops. A single drop is a vertical section underground, where you abseil all the way with a single rope. A pitch may be broken, which means it has a ledge or you need a rebelay.

All combinations of above definitons are possible which results in four different kinds of shafts, for each there may be a list of superlatives. We do not have sufficient data for such lists, and unfortunately there is no official institution collecting such data. As a result we have compiled three lists of info available to us. Although we must admitt this is incomplete, we hope it gives an insight into the dimensions of known natural underground spaces.

Underground Single Drops

Cave	Location	Depth	Explanation
Lukina jama	Croatia	516m	The deepest cave of Croatia is 1,392 m deep and only 1,078 m long. It has a single drop of 516 m, making it the cave with the longest vertical drop in the world.
Velebita	Croatia	513m

Underground Pitch

Cave	Location	Depth	Explanation
Vrtoglavica	Slovenia	603m	This cave, located inside Monte Kanin, has a 603 m pitch.
Brezno pod Velbom	Slovenia	501m	This cave is 541 m deep, but it has a 501 m deep shaft, which is blockesd at -377 m by a ledge.
Höllenhöhle	Austria	450m	Has a 450 m deep shaft.
Altes Murmeltier	Austria	307m	Has a 480 m deep shaft with a ledge and a 307 m deep single drop part.

Daylight shafts

Cave	Location	Depth	Explanation
El Sótano (de El Barro)	Querétaro state, México	410m	The deepest entrance pit of the world is 410 m deep.
Sótano de las Golondrinas	San Luis Potosí, México	376m	It is the second deepest entrance drop of the world, 376 m deep, and a challenge for any caver.