Duvalo is an active geothermal surface feature situated close to the village of Kosel

Kosel

Kosel is a village near Ohrid, in the Ohrid Municipality of the Republic of Macedonia.The village is known for its proximity to the extinct volcano Duvalo, which gives the village and its surroundings a permanent sulphuric scent....

, near Ohrid

Ohrid

Ohrid is a city on the eastern shore of Lake Ohrid in the Republic of Macedonia. It has about 42,000 inhabitants, making it the seventh largest city in the country. The city is the seat of Ohrid Municipality. Ohrid is notable for having once had 365 churches, one for each day of the year and has...

, Republic of Macedonia

Republic of Macedonia

Macedonia , officially the Republic of Macedonia , is a country located in the central Balkan peninsula in Southeast Europe. It is one of the successor states of the former Yugoslavia, from which it declared independence in 1991...

. It resembles a miniature crater with a diameter of 0.5 metre and depth of 30 centimetres. Gaseous carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 and hydrogen sulfide

Hydrogen sulfide

Hydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...

 are released from the hole. It represents the last trace of more significant former volcanic activity, now almost extinct. The Turks during the Ottoman Empire

Ottoman Empire

The Ottoman EmpireIt was usually referred to as the "Ottoman Empire", the "Turkish Empire", the "Ottoman Caliphate" or more commonly "Turkey" by its contemporaries...

used to mine the sulphur.