A stamp for the city of Plovdiv, Bulgaria, which is the oldest in the world. Some cities have their own stamps too, so I think Plovdiv deserves its separate one as well.
It has a lot of beautiful monuments and places, like the Ancient Theatre, Ancient stadium, The Roman Forum and Nebet Tepe.
In 2019, Plovdiv was selected as the European Capital of Culture.
There's more to see, like The Old Town part of Plovdiv and the Dzhumaya Mosque. Feel free to visit! :)