One of the most beautiful assemblages in the history of Hungarian geological and palaeobotanical research, remains of a 7 million years old bald-cypress forest was unearthed in the territory of the open cast lignite mine of Bükkábrány, from 65 m deep in July, 2007. The discovery is unprecedented even at world level, because all of the sixteen exposed stumps were preserved in their original upright position by the sand buried them. The material of the trees were not petrified, and their cell-structure was barely damaged or transformed as compared to recent trees.

The management of the Mátra Power Plant and the Bükkábrány Coal Mine selflessly made the in situ examination of the unique assemblage and its environment by the experts of several scientific institutions possible. The Herman Ottó Museum of Miskolc, and the Nature Reserves Ipolytarnóc Fossils of Bükk National Park got special permission to cut and transport complete trunks from the remains of the forest for making further research and showing them to the general public.

Colleagues of the Herman Ottó Museum sawed four tree-trunks and transported them to Miskolc under the direction of János Veres, research leader. The preservation of the trees was started here immediately with the coordination of Ferenc Bánfalvy, head of department and tree restorer. At the same time, the idea of establishing a new exhibition area, which would introduce the age of the trees, that is the geological Miocene age (23–5.3 mya) was born. Opening of the “Pannon Sea Museum” on 20th November 2013 created an opportunity to re-establish the natural history collection, which was terminated in 1950, under the name of Pannon Sea Repository of Geological and Natural History. With the formation of the repository, the museum set the goal of collecting, researching, preserving and regularly displaying of geological and paleontological memories of the tertiary and quaternary period.