Tadmor, OhioTadmor is an extinct town in Montgomery County, in the U.S. state of Ohio. Its location,, is now within the Vandalia city limits.HistoryA post office called Tadmer was established in 1867, the name was changed to Tadmor in 1884, and the post office closed in 1917. Besides the post office, Tadmor had a station on the Dayton and Michigan Railroad.