Naharayim, historically the Jisr Majami area, where the Yarmouk River flows into the Jordan River, was named by the Palestine Electric Company in a letter dated 27 February 1929 to Palestine Railways giving "proper names" to the "different quarters of our Jordan Works" one of these being the "works as a whole including the labour camp" to be called "Naharaim" and another being the site of the "Power House and the adjoining staff quarters, offices" to be called Tel Or. Wikipedia