The Pannonian Limes is a part that is mostly found in Hungary from the Roman front line known as the Danubian Limes, a line of castles and fortifications along the Danube River. The fortification line included guard towers, legionnaires camps (castra) and forts (castella).
The plaques are located in the March 15 square in Budapest where one of the camps stood, describing the relative location of the camps along the Danube which is also drawn on the sidewalk.
The current plaque shows Intercisa, the Roman name of the old military camp in Dunaújváros, Hungary. The Roman camp was probably established during the reign of Emperor Domitian (end of the first century AD), and was in use until the third decade of the fifth century AD. As can be seen from the chart accompanying the name of the camp, which is different from the icon symbolizing a fortress, it is a rather large Roman camp.
Notice the two lines representing the Danube River on the right side of the plaque.
In the next photo taken on the same day, part of the line of fortresses was seen, with the route of the Danube River between the various plates Click for a larger image