Around the year 210, a line stitched from forts, towers and a timber palisade cut present-day Romania in two. Type your town below and find which side you were on — inside, outside, or right on the frontier.
The Jidava fort on the limes Transalutanus today: the uncovered walls of one of the fortifications guarding the road to the Rucăr–Bran pass. Saturnian, Wikimedia Commons, public domain
Scroll: first the question, then the line, then your answer.
Put a finger on the map of present-day Romania and ask: around the year 210, was this place inside Roman Dacia? The answer is never just “yes” or “no”. It is “yes, from 106 to 271”, or “no — but it had been, a century earlier”, or “so close to the line that not even the archaeologists call it to the kilometre”. The question is only about Dacia: Dobruja, for instance, was in the Empire too, but in another province.
One line, with a date on it: Dacia’s frontier in the early third century, drawn with 210 as a reference date inside a provisional c. 200–245 window — from the Iron Gates to the Eastern Carpathians, from the Someș to the Danube. Of the 15,421 localities of present-day Romania, 6,137 (39.8%) lie inside it, 8,414 outside, and 870 so close to the thread that they earn the only honest verdict: on the frontier.
The line is not drawn from memory. It follows the monograph behind the UNESCO file of the Dacian limes — Breeze, Marcu and Cupcea, 2021 — checked against the 2024 ICOMOS evaluation, and corrected in two places where the DARE digital map, the starting point, contradicts the monograph. All of that is in the method, at the end. First, your question: type your town in the box on the map.
The line
A 1,444-kilometre frontier with a date on it
The red thread is the border of the province of Dacia around the year 210. It follows the Danube, the Olt, the Carpathian ridges, the Someș and the Mureș — 1,444 kilometres of drawn border, rivers included, guarded by a chain of 47 forts.
The whole line, at a glance
The frontier worked from 106, when Trajan finished the conquest, until 271, when the army and administration withdrew on the orders of Aurelian — the span the UNESCO file gives too, with 277 inscribed sites in 2024, in eight sectors. The eastern sector, the limes Transalutanus, alone holds 19 sites; the Olt one, 17; the northern one, 76.
The line on the map is drawn for a single moment in that long span: around the year 210. Then, in the words of the monograph, “most forts here seem to have been occupied” — including on the Transalutanus, “at the beginning of the 3rd century”. Any question of the form “was my town in Dacia?” needs such a moment: without it, the answer is a beautiful lie.
Cut by Hadrian: the line moves
The hollow dots in Muntenia are the forts of Trajan — Drajna de Sus, Târgșoru Vechi and the rest — which guarded a territory the Romans held for twelve years. After the wars of 117–118, Hadrian gave up eastern Muntenia and southern Moldova, and the frontier fell back to the Olt and the Danube.
That is why Ploiești lies outside the 210 line, 80 kilometres from it: Trajan’s nearby forts — Drajna, Târgșoru — show the area had been in the Empire, but it had been given up under Hadrian, a century before the map’s moment. Pitești, on the other hand, sits right on the thread — 1.0 kilometres from it — because by 210 the border had crossed east of the Olt again, onto the Transalutanus. Two moments, two maps: that is why the line carries a date.
The south: the palisade that burned
From the Danube to Boroșneu, across 300 kilometres, the Transalutanus links forts of different construction — earthen most of them, stone-built Jidava: Flămânda, Putineiu, Băneasa, Valea Urluii, Gresia, Ghioca, Urluieni, Fâlfani, Săpata, Albota, Purcăreni, Jidava, Cumidava, Boroșneu. The earthen fort at Gresia was test-trenched in 1996 by Romeo Avram, in a campaign of less than a month.
The scantiness says everything about the sector: at the time of the “Limes Transalutanus” project, not one of the forts south of the Argeș had a proper topographic survey, and the big fort at Băneasa — the largest on the line — loses ground with every ploughing: over 60 centimetres of the upper layers are gone since the 1945 Cantacuzino dig, and the site may vanish within 20–30 years.
Yet this is exactly where the strongest evidence came from. At Băneasa, a barrack room yielded a silver denarius of Septimius Severus struck in 208 and worn, by its wear, for at most 20 years — a circulation estimate, not an exact date: the barrack was in use around the beginning of the 3rd century. And at Valea Mocanului, the 2016 trench showed the “vallum” is no vallum: it is a giant palisade of trunks set in a ditch 1.33–1.61 metres deep, 2–3 centimetres apart, daubed with clay and burned — a timber wall that worked for 4–5 decades, with traps in front and a watch pole 3 metres behind.
That is what the southern frontier looked like — timber, clay and fire at Băneasa and Valea Mocanului, stone at Jidava — and a straight road over 2 kilometres long that still cuts the valley, visible from the air.
The real surprise of the field survey was the civilian settlements: by nearly every fort and — the kicker — exactly on the border line, not somewhere behind it. The one at Roșiori-Măldăeni tops 40 hectares, 20 times the average of the rest. At Roșiori the road itself comes in two variants, the old one to the west and one later shifted north-east, onto the hill above the present-day town — “an excellent observation post toward the barbaricum”.
The Jidava hypocaust: Roman underfloor heating among the ruins of the Transalutanus fort. Saturnian, Wikimedia Commons, public domain
The north: the towers on the Someș
In the north, the frontier is a network, not a wall: forts in the valleys, burgi and towers on the crests — the castra–burgi–turres triple. Between Cășeiu and Ilișua, on the Someș, the towers string along the north–south cuestas, and the first to dig them, in 1857, was Károly Torma, at the personal suggestion of Theodor Mommsen. A century later, Panaitescu (1929) called this a 60-kilometre fluvial limes — a hypothesis contested then, revived later by Ferenczi.
The fort at Ilișua, on the Someș, is listed in the UNESCO file under the ancient name Arcobara — older books call it Arcobadara. The garrison was, “most probably”, the ala I Tungrorum Frontoniana, an auxiliary cavalry unit; what is certain is that the fort and its civilian settlement were systematically researched by the Bistrița archaeologists.
From Ilișua the line runs east down the Someș, passes south of Năsăud and dissolves into the Călimani, where the mountain stood in for a wall. Present-day Bistrița lies 6.1 kilometres inside the thread; Năsăud, hugging the water, falls in the uncertainty band — on the frontier.
The rebuilt praetorian gate at Porolissum, the postcard image of the north-western frontier. Rul3rz, Wikimedia Commons, public domain
The end: the Carpi wars and the withdrawal
The line of around 210 never grew old. Under Philip the Arab, the Carpi plundered the Danube country until the emperor beat them and made peace with them — Zosimus tells the episode, and the Transalutanus sector never recovered. The whole province was abandoned in 270–275, when Aurelian pulled the army and administration south of the Danube.
What remains are the burned ramparts, the coins in the barracks, and the opening question. Scroll back to the map or go to the answer: your verdict is computed on the spot, from the geometry above, with the error in view.
The box below searches 15,421 localities without sending anything over the net: everything is computed right here. If your village is missing, tap the map — any point in Romania gets a verdict.
A few cities, so you can hear how the verdict sounds
Bucharest — outside, 96 kilometres from the line; nearest fort: Valea Urluii, 96 kilometres away.
Cluj-Napoca — inside, 43 kilometres from the line; nearest fort: Cășeiu, 50 kilometres away.
Pitești, Brașov, Zalău, Drobeta-Turnu Severin — on the frontier: 1.0, 1.4, 3.3 and 2.3 kilometres from the thread, respectively.
County seats
Want to walk the frontier? The visitable-sites guide is next door, at Frontiera Dacică — and the Transalutanus layer of the Atlasul istoriei României shows the same sector, with its disputed dating, from another angle.
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The map
How to read the map
The red thread is the border; the pink shadow around it is the uncertainty band, 5 kilometres either side. Solid dots are the 47 forts in the computation file; the hollow ones, in Muntenia, are the forts of Trajan, out of use before the moment of the map. The pin is you, and the thin line leaving it runs to the nearest fort — the distance in the verdict.
The verdict colours are three and only three: the dark green of inside, the grey of outside, the red of the band. On red, the page does not guess: Brașov, for instance — the line passes 1.4 kilometres from its centre, in the corridor between Râșnov and Boroșneu — too close to pick a side.
Today
What you see on the line today
At Jidava, near Câmpulung, the walls are uncovered and visitable: the photo above shows the enclosure, and the hypocaust — Roman underfloor heating — survives among the ruins. It is the handiest place to lay hands on the Transalutanus.
At Porolissum, near Zalău, the praetorian gate has been rebuilt and shows from afar — the postcard image of the north-western frontier, though its stone is new. And at Gresia you see nothing: the earthen fort sleeps under the plough, known from the 1996 test trenches and the 1903 map. The page shows it on the map precisely because its story is invisible.
The Gresia fort was test-trenched in 1996; its dot on the Transalutanus line is an approximate position, not a proven one. Absence is information too — it says where the next trench should go.
Questions
Three natural questions
Why the year 210 of all years?
Because then, in the words of the monograph, “most forts here seem to have been occupied”: the Transalutanus at the beginning of the 3rd century, the rest of the frontier across 106–271. A century earlier, the south-east would have answered differently: Trajan’s Muntenian forts still stood, west of the later line; half a century later would have caught the collapse. The line holds, roughly, for the first decades of the 3rd century.
My town is on the frontier. Does that mean nothing is known?
It means the opposite: “on the frontier” means that your selected point lies within 5 kilometres of the reconstructed line, and the line, in your stretch, is not fixed to the kilometre — either it runs through a road corridor (Pitești, Brașov), or it follows a river (Năsăud), or specialists dispute it (the Banat). It is an answer, not an evasion.
But Dobruja? It was in the Empire too.
It was — but in another province, Moesia Inferior, with another limes, the Danube one. The question here is only about Dacia: Constanța comes out “outside”, 267 kilometres from the line, which is right for Dacia and incomplete for the Empire. Dobruja deserves its own page; this one is about the land border of Dacia.
Method
How the line is drawn (and where it lies least)
The line has a date — around the year 210 — and an author: it follows the course of the frontier in Breeze, Marcu and Cupcea, The Roman Frontiers of Dacia (2021), the monograph behind the UNESCO file, checked against the 2024 ICOMOS evaluation (frontier operational 106–271). The moment 210 is chosen because then, in the words of the monograph, “most forts here seem to have been occupied”: the Transalutanus “at the beginning of the 3rd century”, and the 208 coin from Băneasa catches it alive then too.
The geometry starts from the DARE digital map (Johan Åhlfeldt, Lund University, CC BY-SA): the Dacia polygon and the two Olt lines. Checked stretch by stretch, DARE fails in two places: in the north it bloats the province to Satu Mare, and in the south-east it follows the Olt and leaves the whole Transalutanus strip outside — Gresia included. Both are corrected on the record: the north along the Tihău–Cășeiu–Ilișua fort line and the Someș — Panaitescu’s fluvial limes, revived by Ferenczi — the south-east along the Transalutanus line itself. Beyond the northern thread, north and west, stretches a 10–25 km-deep belt of towers and burgi: “outside” just north of the line means outside the fort line, not necessarily outside the Roman world. Details, with the moved vertices, are in the research file of the line.
The uncertainty band runs 5 kilometres either side of the thread: the precision of DARE (2 kilometres) plus interpolation between forts plus the two disputed stretches (the Banat and the north-eastern corner). Whoever falls in the band gets “on the frontier”, never a forced verdict. Large distances in the text are rounded to the whole kilometre, band ones keep a decimal; exact values are in the downloadable data.
The 47 forts behind “nearest fort” are positioned from DARE and OpenStreetMap: 25 mapped, 22 approximate (village coordinate or on-line interpolation, 1–3 kilometre error). Rankings can wobble between two close approximates — Bistrița is 7.5 km from Livezile and 8.2 km from Orheiu, both approximate. Mind one trap: where DARE and OpenStreetMap agree to a hundred metres, they usually share a source — the agreement is not independent verification, and the page marks it as such.
What is still unopened: the UNESCO table with the coordinates of the 277 sites (download blocked), the dating study of Teodor in Cercetări Arheologice 29.2 (blocked), the 1997 Ilișua volume of Protase, Gaiu and Marinescu (not found openly) and the 1996 Gresia campaign of Avram (cited via Teodor & Ștefan, 2014). When they open, the line gets recalibrated — and the page will say so.
Sources
The line and its dating
Breeze–Marcu–Cupcea 2021 (open access); the 2024 ICOMOS evaluation of UNESCO file 1718; Zosimus on the Carpi war of Philip; DARE (CC BY-SA) as the starting geometry, verified and corrected.
The two sectors
Teodor & Ștefan 2014 and the “Limes Transalutanus” project reports for the south; Zăgreanu et al. 2017 (JAHA) for the north; the 1903 Vaschide map for the fort order.
Data and pictures
GeoNames (CC BY 4.0) for localities; OpenStreetMap (ODbL) and Natural Earth (public domain) for geography; the Jidava and Porolissum photos (public domain, Wikimedia Commons). Neighbours: Atlasul istoriei României, Frontiera Dacică.
