Roman Well in Belgrade fortress built by Austrians in Ottoman times is only possible in Serbia, but it makes perfect sense. After constant Turkish attacks on Austria, Austrians finally decided to counter attack and move battlefield to Turkish territory, present day Serbia.
First such attempt happened 1688, but by 1690, Austrian army led by Maximilian of Bavaria was pushed back north alongside their Serbian allies. Large portion of Serbian population then left their homeland and settled in Austria where they were given special privileges in return for army obligation.
Second such Austrian campaign in Serbia was led by legendary Prince Eugen of Savoy in 1717. This is when, so called Roman Well was constructed in Belgrade Fortress. Austrian’s army first engineer, Nikola Doxat did not build only Roman Well, but so called Baroque Belgrade as well, that was financed by almost whole of Europe. Unfortunately, Baroque Belgrade did not survive Turkish recovery, except in only few cases such as Roman Well in Belgrade Fortress. Therefore, Roman Well is actually Austrian, but controversy doesn’t stop there. Well is actually a cistern, not a well at all that housed some of the most horrifying Belgrade stories that managed to inspire famous director Alfred Hitchcock when he visited Yugoslav capital back then.
Third Austrian attempt, also unsuccessful, was led by Marshal Laudon. Serbian troops under Marshal’s command acquired military skills necessary for Serbo-Turkish confrontations that were to follow in two Serbian uprisings.