Adjoining Galway Bay to the north, the Burren Plateau (Burren is Gaelic for “stony place”) is an example of karst terrain. Karst terrain is generally formed when sedimentary rocks are dissolved by groundwater. This astronaut photograph illustrates the northwestern-most portion of the Burren Plateau, which is characterized by the distinctive bare exposures of almost horizontal, layered Paleozoic-age limestone rocks that form Gleninagh Mountain.
The Semien Mountains are the highest parts of the Ethiopian Plateau (more than 2,000 meters; or 6,560 feet). They are surrounded by a steep, ragged escarpment (step), with dramatic vertical cliffs, pinnacles, and rock spires. Although the plateau lies in the latitude of the Sahara–Arabia deserts, its high altitude makes for a cool, wet climate. In fact, the Semien Mountains are one of the few places in Africa to regularly receive snow, and they receive plentiful rainfall (more than 1,280 millimeters, or 55 inches). The moderate climate is shown by light green vegetation on the mountains, compared with the brown canyons, which are hot and dry.