The Trigrad Gorge is a canyon of vertical marble

Marble

Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.Marble is commonly used for...

 rocks in the Rhodope Mountains

Rhodope Mountains

The Rhodopes are a mountain range in Southeastern Europe, with over 83% of its area in southern Bulgaria and the remainder in Greece. Its highest peak, Golyam Perelik , is the seventh highest Bulgarian mountain...

 of Bulgaria

Bulgaria

Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...

's very southern parts.

The gorge encloses the course of the Trigrad River that plunges into the Devil's Throat

Devil's Throat Cave

Devil's Throat Cave, or Dyavolsko Garlo, is located in the western Rhodopes in Bulgaria, near its border to Greece. A popular tourist attraction, Devil's Throat branches from Trigrad Gorge.- Mythology :...

 cave and 530 m further comes out as a large karst

KARST

Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...

 spring. It laters flows in to the Byunovska River.
The gorge's west wall reaches 300 m in height, while the east one extends up to 300–350 m. In the beginning, the distance between the two walls is about 300 m, but reaches about 100 m in the north. The Trigrad Gorge is located 1.2 km from the village of Trigrad at 1,450 above sea level and has a total length of 7 km, of which the real part is 2–3 km.

Honour

Trigrad Gap

Trigrad Gap

Trigrad Gap is a saddle of 500 m height in the Delchev Ridge in the Tangra Mountains of eastern Livingston Island in the South Shetland Islands, Antarctica. The gap is bounded to the southwest by Spartacus Peak and to the northeast by Yavorov Peak. The feature is named after the Bulgarian...

 on Livingston Island in the South Shetland Islands

South Shetland Islands

The South Shetland Islands are a group of Antarctic islands, lying about north of the Antarctic Peninsula, with a total area of . By the Antarctic Treaty of 1959, the Islands' sovereignty is neither recognized nor disputed by the signatories and they are free for use by any signatory for...

, Antarctica is named after Trigrad settlement and gorge.