The Cheile Dobrogei geological reserve has a total area of almost 11,000 ha. The Calcar mountains reign over the entire region. In time, they have acquired different shapes, reminding the fact that, once, Dobrogea lied on the bottom of the sea. The Calcars have an organic origin coming from the coral reefs that used to populate the tropical waters 205 million years ago. From a paleontological point of view, the calcars in Cheile Dobrogei host the richest fossils with Meso-Jurassic fauna. Many enchanting natural attractions are found here.