The Blue Stones Nature Park is located in the immediate vicinity of the town of Sliven. It is an area of high and medium importance for the protection of biological diversity. It is characterized by a pronounced mountainous relief. On the territory of the nature park there are many rock phenomena, popular natural features and places for recreation, the most famous one being the rock phenomenon "Halkata" (the Ring). The phenomenon is among the most visited sites in the Blue Stones Nature Park near Sliven. The tourist itinerary is relatively easy, the path starts from the lower station of the lift that leads to the Karandila area.