Zvonivá jama Abyss
It is located in the central part of the Plešivská Plateau, called Moon Country, with a surface divided by a number of dolines. Inside one of them, there is the entrance to the corrosion-collapse abyss 100,5 m deep. It is formed in the Mesozoic Middle Triassic pale Wetterstein limestones of th Silica Nappe.
The entrance vertical shaft ends in the depth of 45 m with a great underground dome with a mighty debris cone on the bottom. Its top is 84 m from the surface opening. Along the sides of the dome there are inclined ascending passages 180 m long, which originated in connection with underground draining of adjacent large dolines. The underground waters from the abyss penetrate to the Nová Brzotínska Cave, which opens to the surface by a spring on the right hand side of the Slaná River canyon. The entrance shaft was formed by corrosion of atmospheric waters percolating along the crossing tectonic faults. There are pagoda stalagmites more than 10 m high in the abyss. The highest one has 26 m.
The abyss is an important wintering place for bats. By now 7 bat species were recorded here, with the most abundant Lesser Horseshoe Bat (Rhinolophus hipposideros) and Barbastelle (Barbastella barbastellus). The invertebrates comprise rare cave pseudoscorpion Neobisium (Blothrus) slovacum, which was the first time discovered in nearby Diviačia Abyss.
Abyss opening is known for a long time. The first descends date back to 1875 and 1882. The first vocational description is from 1925.