A makhtesh (Hebrew: מַכְתֵּשׁ, plural: מַכְתְּשִׁים – Makhteshim) is a geological landform considered unique to the Negev desert of Israel. 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.