Romania has relatively few preserved ancient vestiges, especially when it comes to fortifications. The earthworks - the limes / palisades - had an important role in the defensive fortification north of the Danube, the area being vulnerable to attacks from Central Europe, but also from the North-Pontic area. Thus, limes were built by the Romans, the Goths and the Byzantines. Most of these limes have been lost in time and they are preserved only in places, in small vestiges, and in documentary attestations. For many of these there is little definite attestation, and historians - often motivated by political significance - contradict themselves as to the period of construction and its authorship. If we look at the case of other similar limes in the world, most of the time they were built by the Romans and then they were maintained and expanded by the populations that succeeded them, whether these populations remained in those places until today, whether they migrated.
In Romanian folklore, the limes survived until recently, most often under the generic name of "Trajan's wave" or "Trajan's furrow", although obviously not all were built by the same Roman emperor. Echoes of the waves of the earth, in a mythologized context, broken from the original meaning of limes, are also in the versions of Plugușor, a traditional New Year's poem/oration.
The most famous is Zidul lui Constantin / Brazda lui Novac. This was part of the defensive line on the Danube, the Limes Moesiae, which stretched from the Danube Delta to Pannonia, with fortifications on both banks. The Limes of the Romanian Plain stretched between Siriu / probably; according to other sources the river Buzău /, followed the boundaries of the Getic Plateau and reached the line of the Danube at Drobeta. According to wikipedia:
The furrow of northern Novac is a limes, reinforced with an earth mound, built in the 4th century, at the time of Emperor Constantine the Great, which crosses Argeș county from west to east, intersecting the Transalutanus earth mound in the village of Urlueni. The ditch lies to the north of the wave, indicating that it was intended to defend the territory south of this boundary. At the time of construction, the wave was 3 m high and the ditch 2 m deep. Its length was about 700 km.
Currently, Brazda lui Novac de Nord constitutes the support of the embankments of the Curtea de Argeș-Pitești-Roșiori de Vede-Turnu Măgurele railway.Also in that source you can find information about the Northern Novac Furrow, the Southern Novac Furrow / or the Trojan / and about the archaeological classification of the remains of this/these wave/s. Link: https://ro.wikipedia.org/wiki/Brazda_lui_Novac_(limes)
Other limes on the current territory of Romania or in the immediately adjacent area are: The Roman Road that crossed from south to north the center of Muntenia east of the Olt River – Limes Transalutanus, with a length of 225 km and that reached the Rucăr-Bran area ; Limes Alutanus - on Olt - which was less a mound of earth than a system of border fortifications and extended to the northern part of Transylvania; Greutungi Wall / Northern Trajan's Wall - in the central area of Bessarabia - 120 km; The Antharic Wave / South Trajan's Wave – in the south of Bessarabia, today Ukraine, between Bolgrad and the Sasic lagoon; the waves of the Western Plain – a succession of three distinct limes west of Romania.
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