The land was also declared protected by the Roman Emperor Hadrian in year 134 AD as the following was found engraved on a rock in the upper west side of Yammouneh: “I, Emperor Adriano, make the area of Yammouneh a protected reserve and shall forbid anyone to cut Juniper trees therein.”
The valley holds traces of many ancient civilizations such as Phoenician, Roman, and Arab.
There are a Roman temple and Byzantine ruins. What remains of the temple today is a wall of limestone blocks that goes below the lake level, where there were supposedly the subterranean chambers dedicated to goddess Astarte (Venus).
A group of ruins of an ancient fort located there is said to have served as the summer house for Emperor Adriano.
The village lies on the Yammouneh Fault line that was responsible for several historical earthquakes that happened there. A new section of the fault was discovered in 2010 by Ata Elias of the American University of Beirut.
The valley has become a popular attraction for people who want to visit the many cannabis fields of Bekaa.
#10 Early Sanctuary of El
Some Ugaritic texts (1200 BC) revealed to Professor Marvin H. Pope of Yale University that Yammouneh was home to an ancient sanctuary dedicated to El (God). (“El in the Ugaritic Texts”, Vetus Testamentum, Supplement, II – 1955:61ff).