In the Hargita volcanic mountain range in Transylvania, there are two volcanic craters, around which there is a unique European natural reservation.
In one of these craters the only volcanic lake in Romania was formed: Saint Anne Lake, and in the second lake there is an oligotrophic swampy area of 80 ha, namely Mohos, located at 1050 m altitude. The peat bog is one of the most important botanic nature reserves in Europe. It is part of the Mohos Nature reserve. The surface of this bog is almost 4 times larger than that of the Lake St. Anne, and its depth reaches 20 m in some places. The birth certificate of this reservation is lost in the mists of time, 30,000 years ago. The crater that houses the Mohos erupted first, forming a lake. The volcanic ash thrown when the second crater erupted, clogged this lake, forming the peat moss, which gives an almost black shade to the 20 meshes of water scattered on the surface of Mohos.

Another history of the place leads us over the years 2012-2014, when the peat bog was attacked by xylophagous swamp insects, which destroyed a large part of the wild pines and especially the birches in the tree population.