In 1823 Hemprich and Ehrenberg sailed across the Gulf of Suez to El Tur on the south-west coast of the Sinai peninsula, remaining there for nine months. During this time they visited Mount Sinai, and Ehrenberg became one of the first naturalists to study the marine life of the Red Sea. In 1824 they visited the Lebanon, travelling inland from Beirut to the summit of the Jebel Liban and making their base at Bcharre. In August they returned to Egypt.