Serabit el-Khadim is a locality in the south-west Sinai Peninsula where turquoise was mined extensively in antiquity, mainly by the ancient Egyptians. Archaeological excavation, initially by Sir Flinders Petrie, revealed the ancient mining camps and a long-lived Temple of Hathor, the Egyptian goddess who was favoured as a protector in desert regions.
Fewer than thirty incised graffiti in a "Proto-Sinaitic script" found in the temple have made Serabit el-Khadim famous among students of the history of the alphabet. The mines were worked by prisoners of war from southwest Asia who presumably spoke a Northwest Semitic language, such as the Canaanite that was ancestral to Phoenician and Hebrew. Despite a century of study after their initial publication by Sir Flinders Petrie, researchers can agree on the decipherment of only a single phrase, cracked in 1916 by Alan Gardiner: לבעלת l bʿlt (to the Lady) [baʿlat (Lady) being a title of Hathor and the feminine of the title Baʿal (Lord) given to the Semitic god], although the word m’hb (loved) is frequently cited as a second word.
The script has graphic similarities with the Egyptian hieratic script, the less elaborate form of the hieroglyphs. In the 1950s and 60s it was common to show the derivation of the Canaanite alphabet from hieratic, using William Albright's interpretations of Proto-Sinaitic as the key. It was generally accepted that the language of the inscriptions was Semitic, that the script had a hieratic prototype and was ancestral to the Semitic alphabets, and that the script was itself acrophonic and alphabetic (more specifically, a consonantal alphabet or abjad). The word baʿlat (Lady) lends credence to the identification of the language as Semitic. However, the lack of further progress in decipherment casts doubt over the other suppositions, and the identification of the hieratic prototypes remains speculative.
In her book, "A History of Sinai", Lina Eckenstein theorized that Serabit el-Khadim was the historical site of Mt. Sinai where Moses received the 10 commandments. This theory comes in no small part to the site containing a temple of Hathor which is believed to be the Golden Calf idol constructed by the Hebrews while Moses was on the mountain top.
The local tribes are responsible for protecting the site from looting and are open to assisting tourists and hiring out as guides.