Climber's Challenge is a term used to describe the physical and mental challenge of climbing mountains, crags, cliffs, and other alpine terrain. CRAG, with four letters, is a steep, rugged rock face or CLIFF. EVEREST, with seven letters, is the highest mountain in the world, located in the Himalayas. CLIFF, with five letters, is a high, steep, or overhanging face of rock. ALP, with three letters, is an abbreviation for the Alps, a large mountain range in Europe.