The Stob Earth Pyramids () are rock formations, known as

hoodoos A hoodoo (also called a tent rock, fairy chimney, or earth pyramid) is a tall, thin spire of rock formed by erosion. Hoodoos typically consist of relatively soft rock topped by harder, less easily eroded stone that protects each column from the ...

, situated at the foothills of the

Rila Rila (, ) is the highest mountain range of Bulgaria, the Balkans, Balkan Peninsula, and Southeast Europe. It is situated in southwestern Bulgaria and forms part of the Rila–Rhodope Mountains, Rhodope Massif. The highest summit is Musala at an e ...

mountain range in south-western

Bulgaria Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...

. They span an area of 0.7 km² near the village of Stob,

Kyustendil Province Kyustendil Province () is a province in southwestern Bulgaria, extending over an area of (constituting 2.7% of the total territory of the Republic of Bulgaria), and with a population of 106 131. It borders the provinces of Sofia, Pernik, and ...

. The rock formations are up to 12 m high and up to 40 m thick at the base. Their shape is mostly conical to mushroomlike. Some of the columns are topped by flat stones.

Location

The Stob Earth Pyramids are located at the western foothills of the

mountain range in the

Balkan Peninsula The Balkans ( , ), corresponding partially with the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throug ...

at an altitude between 600 and 750 m. They occupy the Klisura ridge facing the valley of the

Rilska River The Rilska River (, ''Rilska reka'', "Rila River") is a river in south-western Bulgaria, a left tributary of the Struma (river), Struma. The river is 51 km long and drains the western sections of the Rila mountain range. Geography Under t ...

, a left tributary of the Struma. They are situated at less than one kilometre east of the village of Stob in

Kocherinovo Municipality Kocherinovo Municipality is a municipality in Kyustendil Province, Bulgaria. The administrative centre is Kocherinovo Kocherinovo (, ) is a town in southwestern Bulgaria, part of Kyustendil Province. It is the administrative centre of Kocherino ...

. They lie some 83 km south of the national capital

Sofia Sofia is the Capital city, capital and List of cities and towns in Bulgaria, largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain, in the western part of the country. The city is built west of the Is ...

and 18 km north of the city of

Blagoevgrad Blagoevgrad ( ) is List of cities and towns in Bulgaria, а town in Southwestern Bulgaria, the administrative centre of Blagoevgrad Municipality and of Blagoevgrad Province. With a population of almost inhabitants, it is the economic and cultura ...

Geology and formation

Geologically, the Stob Earth Pyramids are part of the Blagoevgrad

Graben In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German language, German, meaning 'ditch' or 't ...

that consists of lakebed, alluvial and sloping deposits dated from the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

epochs. They are built up by

Precambrian The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of t ...

metamorphic rocks. There are two

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...

s: the Dzherman Formation consists of aleurolite, clay and sandstone; the Barakovo one is built up by conglomerate and sandstone. During the Pliocene the area was at the bottom of a shallow lake and accumulated sediments that form a 200 and 250 m thick stratum consisting of little fragments with a lot of clay. The colour is dull white to yellowing. It forms the foundations of the pyramids but the erosion reveals only small patches this layer. The Pleistocene stratum above is reddish with alternating layers of cobble conglomerate and lightly soldered sandstone, as well as larger rock pieces originating from the slopes of Rila. The principal factor for the formation of the Stob Earth Pyramids is erosion due to rainfall. The rain drops penetrate the lightly soldered sediment and continuously wash it away. The location of the rock pieces in the stratum determines the place, size and shape of each pyramid because they prevent the abrasion of the layers below. They are covered by a 1 cm thick coat of hardened sun burned clay which protects the fragile sandstone and delays the erosion.

Description

The Stob Earth Pyramids vary in shape from sharp through conical to mushroomlike. About half of the formations are crowned by rocks, whose area is sometimes two to three times larger than the cross-section of the pyramid below. Their height averages some 6 to 10 m but can reach up to 12 m; the thickness at the base is up to 40 m. Most of them are facing in southern direction but there are also a few grouped together on the northern slopes of the ridge overlooking Stob. Groups of individual Pyramids have been named the Towers, the Brothers, the Hammers, the Wedding Couple, the Pinnacles, the Samodiva Chimneys, etc. They are a tourist destination, although not as popular as the much larger

Melnik Earth Pyramids The Melnik Earth Pyramids () are rock formations, known as Hoodoo (geology), hoodoos, situated at the foothills of the Pirin mountain range in south-western Bulgaria. They span an area of 17 km2 near the town of Melnik, Bulgaria, Melnik, Bla ...

. The rock formations are easily accessible via the

Struma motorway The Struma Motorway (, ) is a motorway currently under construction in Bulgaria. The motorway is located in the Yugozapaden area in South West Bulgaria, and follows the route Sofia-Pernik- Dupnitsa-Blagoevgrad-Sandanski to Kulata on the border ...

and the parallel first class I-1 road that form part of

European route E79 European route E 79 is a road part of the International E-road network. It begins in Miskolc, Hungary and ends in Thessaloniki, Greece, also running through Romania and Bulgaria. The road is long. Itinerary The E 79 routes through ...

along the Struma valley. The third class III-107 branches from I-1 at the municipal centre

Kocherinovo Kocherinovo (, ) is a town in southwestern Bulgaria, part of Kyustendil Province. It is the administrative centre of Kocherinovo Municipality, which lies in the southern part of Kyustendil Province. As of 2013 it had 2,255 inhabitants. Kocherino ...

and heads for 7 km to north-east to Stob. The Stob Earth Pyramids were declared a natural landmark in 1964 with a total extension of the protected area of 7.4 hectares, or 0.74 km².

Citations

References

External links