This is a list of fortifications past and present, a fortification being a major physical defensive structure often composed of a more or less wall-connected series of forts.
Limes Moesiae - defensive frontier system in Southeast Europe, a collection of Roman fortifications between the Black Sea shore and Pannonia, present-day Hungary, consisting primarily of forts along the Danube (so-called Danubian Limes) to protect the Roman provinces of Upper and Lower Moesia south of the river
