Vlčí jámy Nature Monument (Wolf Hollows) is located on the southwest slope of Blatenský vrch (Blatná Hill). It is a rocky gorge approximately 25 metres deep, 40 metres wide and 200 metres long. The bottom is full of fallen boulders and the sides are perforated with dark caverns. The nature monument is not the work of nature but the result of tin mining activities from the 16th to the 18th century. Adits collapsed in the undermined areas creating a huge hollow, which was later called Wolf Hollow. Its wild character is augmented by the surrounding high forest stands.
Ledová jáma (Ice Pit), a very narrow cave-in (remnant of the Jiří Mine) up to 15 metres deep, is situated closer to the hilltop. According to historical documents, the mine was 50 metres deep. Even in the hottest summer, you will feel the cold rising from the former mines where ore had been exploited by means of the room and pillar method. The climate is so cold that ice and snow did not melt all year. Due to the profile of the Ice Pit, air circulation is hardly perceptible and the pit got its name because cave ice has not melted even in hot summer months for centuries.
Unfortunately, a couple of German pranksters took the snow from the cave home with them in 2006. The reason for their doing was apparently a radio competition in making a snowman in hot summer. Anyway, the youths did not win the competition and they were at the risk of paying a fine of several thousand crowns for causing damage to the nature monument. Maybe it was the snow theft or the very warm winters in 2006 and 2007 that caused the melting of snow and ice in the Ice Pit many long centuries.
The second site known as Vlčí jáma (Wolf Hollow) is named after the Wolfgang Mine that is situated a bit lower. The Wolfgang Mine was one of the largest mines in the mining district of Horní Blatná. In the 16th century, a large room was excavated in a depth of almost 25 metres, the ceiling of which subsequently collapsed. In the course of time, rock from the sides broke loose and the Wolf Hollow thus became wider. The 16th century mining workings reached a maximum depth of 35 metres under the surface. In the 18th century, the local lode was excavated up to the depth of 60 metres and gradually exploited up to the depth of 80 metres – i.e. on a rather large scale in its time. Today, we may look at the interesting natural and technical monument from a look-out point at the beginning of the sink-hole. Remains of old chimneys and drifts, hardly allowing the miners to squeeze through them, may be seen from the top edges.