The Apel-stones, named after the writer Theodor Apel from Leipzig who commissioned them, mark important events during the Battle of Leipzig. There are 50 all in all. They were sculpted by A. F. Aster and put up between 1861 and 1865.
Details of the Apel-stones are on the German wikipedia under Apelsteine
Wikipedia https://en.wikipedia.org/wiki/Apel-stones
Address 56 Max-Liebermann-Straße, Leipzig 04157, Germany
Coordinates 51°22'31.457" N 12°21'39.532" E
