Museum of Natural History is the oldest and largest museum in the city. Here there are collections of minerals, crystals, entomological collections, herbariums. But the main treasure is petrified trees. This natural artifact was formed 290 million years ago as a result of a volcano eruption. First trees were discovered in Chemnitz in 1737 and are continuously being found even today. The last exhibit – a several metres tall horsetail – was found by the scientists in 2008 during excavations in Hilbersdorf. Chemnitz collection is one of the biggest in the world. Notwithstanding its world importance, the museum of natural history doesn’t have its own building and is presently located in the former department store.