The cave was first mentioned in the records in 1541. In 1686,
Gottfried Wilhelm Leibniz visited the cave and wrote a report about it mentioning the local trade with
unicorn artefacts. In those days, fossilized bones supposed to be from unicorns were ground and used for making medicine. In the 17th century,
Otto von Guericke, the mayor of
Magdeburg, wrote a newspaper article about the finding of some ancient animal bones in the Zeunickenberg, a Harz mountain near
Quedlinburg. Based on Guericke’s writings, Leibniz drew a fictional reconstruction of the unicorn's skeleton using the bones that had been found in the cave and published the drawing in his book
Protogaea. In 1872,
Rudolf Virchow carried out an excavation there and determined that the unknown bones actually stem from extinct animals like mammoths and cave bears. Over 70 species of animal have been identified from the many bones that have been found, including 60 species of mammal; amongst them the
cave lion and the
wolf. In 1905, the Unicorn Cave was made accessible to visitors by the construction of an entrance gallery. Since then, of the total length of have been opened up as a show cave. The Unicorn Cave is one of the three information centres of the
Harz – Brunswick Land – Eastphalia National Geopark. The Unicorn Cave has a checkpoint (no. 101) which is part of the
Harzer Wandernadel network of hiking trails. In 2021, the
Giant deer bone of Einhornhöhle was found in the cave, the oldest piece of European art ever discovered, and attributed to Neanderthals. ==Folklore==