The cave region near the Asenovgrad village of Dobrostan is the largest in the Western Rhodopes. It is extremely rich in karst caves - there are about 200, but Dobrostanski Biser is the only one suitable for visits and one of the most beautiful. It is also known as "Ahmet's hole". It is located on the right bank of the Sushitsa River near the village of Dobrostan and is about 2 km from Martsiganitsa hut. The path leading to it is marked and easy to cross. The road to the hut is asphalt. It is not working at the moment, so it is good to provide yourself with water and something to eat.
The cave was first explored in 1963 and opened to tourists in 1990. However, in the last 20 years, the lighting has been broken, part of the iron staircase has been stolen, and the site has become dangerous. The beautiful rock pearls that gave it its name have also been destroyed forever. Cave pearls are spherical formations that are formed when water drips with a suitable chemical composition in a shallow pond and are very beautiful. They are beautiful only in their natural environment.
The cave was renovated and open to visitors in 2018, and this year the season opens on June 10, Friday from 9:00 am. It is not large - between 500 and 1,000 square meters, 15 meters is the depth of the entrance plumb. All three karst forms can be observed here - stalactites, stalagmites and stalactons. A special attraction are the cave lakes. They are arranged like a cascade one below the other, each filling the next and the water is so clear that they seem empty.
Opening hours are from 9:00 am to 6:00 pm on Fridays, Saturdays, Sundays, Mondays and Tuesdays. Wednesday and Thursday are days off. There is a possibility for the site to work on those days for a group of 20 or more visitors by prior request, made not less than 48 hours before the visit.
The individual ticket costs BGN 5. The entrance fee for pupils, students and pensioners is BGN 4. For organized groups of eight people the entrance fee is also BGN 4. Families and parents with children are charged with a single ticket of BGN 12.
Those who want a tour guide should pay: a total of BGN 10 for an ordinary one; a specialized one is BGN 12; and BGN 12 in English.
It is closed for visits since October, so as not to disturb the hibernation of the bat colonies which live there. Apart from Dobrostanski Bisetr, bats spend the winter in colonies in the caves Ivanova Dupka, Kargina Dupka and Ivanova Voda. Extremely famous are 3 other caves - Druzhba, Lednitsa, where the snow stays until June-July and Topchika - it is located above the riverbed Sushitsa and images of horses, goats and deer painted by primitive people were found there. Entry into these caves is prohibited.