The oldest archaeological finds from the site Kokino date back to the Early Bronze Age. Volcanic activity from the lava at the crater peak created rocks that became major markers for the purpose of following the cycles of the Sun and the Moon and measure time. It is ranked fourth oldest observatories by NASA. About an hour away there is the archaeological site called Cocev Kamen (Stone), another spectacular rock formation and prehistoric observatory similar to Kokino and Stonehenge in the UK. This site was used for sacrificial rituals and as a temple. In early times, the entrance to the rock was closed-off by massive wooden gates, you can still see the holes that were cut in the rocks to support gates and piles. And last, but not least is the small medieval town Kratovo, founded in the middle of a once-volcano crater.