Geography of Bulgaria - Topography

Topography

The relief of Bulgaria is varied. In the relatively small territory of the country there are extensive lowlands, plains, hills, low and high mountains, many valleys and deep gorges. The main characteristic of Bulgaria's topography is alternating bands of high and low terrain that extend east to west across the country. From north to south, those bands (called geomorphological regions) are the Danubian Plain, Stara Planina, the Transitional region and the Rilo-Rhodope Massif. The easternmost sections near the Black Sea are hilly, but they gradually gain height to the west until the westernmost part of the country is entirely high ground.

Table showing the distribution of the height zones in Bulgaria:

More than two-thirds of the country is plains, plateaus, or hilly land at an altitude less than 600 m. Plains (below 200 m) make up 31% of the land, plateaus and hills (200 to 600 m) 41%, low mountains (600 to 1,000 m) 10%, medium-sized mountains (1,000 to 1,500 m) 10%, and high mountains (over 1,500 m) 3%. The average altitude in Bulgaria is 470 m.

The contemporary relief of the country is a result of continuous geological evolution. Due to that evolution there are magmatic, sedimentary and metamorphic rocks of different origin, age and composition. Their formation began more than 500 million years ago during the Precambrian and continues till now. The Bulgarian lands were often submerged by ancient seas and lakes, some land layers rose others sank. Volcanic eruptions were common both on land and in the water basins.