Peak in the Himalayas. Located on the Nepal-China boundary and reaching 27,890 ft (8,501 m), it is one of the world's highest mountains. It is sometimes considered part of Mount Everest's massif because it is joined to that peak by a 25,000-ft (7,600-m) ridge. The Swiss climbers Fritz Luchsinger and Ernest Reiss made the first ascent of the mountain in 1956. Lhotse is Tibetan for south peak. E1 was its original survey symbol, denoting Everest-1, given it by the Survey of India in 1931.