Protected by UNESCO, Messel quarry has the most valuable collection of fossils in the world, dating back to the period of more than 46 million years. There used to be a volcanic lake in this place, surrounded by tropical forests. As a memory of that, fossils of 100 families of plants, 50 types of birds, 30 types of invertebrates remained and were collected here. There are also several types of reptiles, fish and amphibians preserved here. One of the most important finds are the remains of the Messel horse. This animal was about the size of a dog and was the progenitor of the modern horses. In the reserve you can observe the quarry from the observation deck (only as a part of a group), while in the museum in the Messel settlement you can see the fossils.