Makhtesh - online puzzles
A makhtesh (Hebrew: מַכְתֵּשׁ ([maχˈteʃ]), plural: מַכְתְּשִׁים ([ˈmaχtəˌʃim] – Makhteshim) is a geological landform considered typical for the Negev desert of Israel and the Sinai peninsula of Egypt. A makhtesh has steep walls of resistant rock surrounding a deep closed valley, which is usually drained by a single wadi. The valleys have limited vegetation and soil, containing a variety of different colored rocks and diverse fauna and flora. The best known and largest makhtesh is Makhtesh Ramon.