Eger Graben

The Eger Graben (much less commonly called the Ohre or Ohře Graben; Czech: Oherský rift, German: Egergraben) is a geological structure in the Czech Republic.

The Ohře (equally commonly known in English by its German name Eger, hence the name of the trough) flows through the Eger Graben and separates the Ore Mountains from the Slavkov Forest and the Doupov Mountains.

The trench continues to the northeast along the valley of the Bílina and later, as the North Bohemian Basin, separates the Ore Mountains from the Bohemian Central Mountains, where the River Ohře leaves the graben and flows into the Elbe south of the Bohemian Mountains.

It was formed by the almost complete erosion of the Variscan Mountains and sits on a fault-block caused by the horizontal pressure of the African continental plate.

The trench thus follows the main fault line of the Ore Mountains.

The Hans Heiling Rocks on the Ohře west of Karlovy Vary : Variscan granite of the Bohemian Massif just south of the southern fault line of the graben in the Sokolov Basin.
Mravenčák (left) and Černý vrch, two tephrite - basanite kuppen on the northern edge of the Doupov Mountains opposite Klášterec nad Ohří
The Bořeň near Bílina , an isolated tephrite-basanite erosion stump on the transition from the Central Bohemian Uplands into the Most Basin