Ruins of the Roman fortress of Noviodunum near Isaccea, third view

Roman & DacianDobruja & the Black Sea

Castrum Noviodunum: the Roman fortress and Danube fleet base

Castrum Noviodunum (Noviodunum ad Istrum) is a Roman fortress and city on the Danube, about 2 km east of Isaccea in Tulcea County, Romania. It was the headquarters of the Roman Danube fleet and, later, of the Legio I Iovia. Excavated towers of the southern wall hint at its former power.

On this Danube bank a Persian king once built a bridge of boats, and later the Romans parked their river fleet here and raised one of the largest towers they ever built.

WhereOn the Danube bank, about 2 km east of Isaccea, Tulcea County, Romania

TypeRoman legionary fortress and naval port, 1st–7th centuries AD

Best forRoman frontier history, the Danube fleet and the large towers of the southern wall

Getting thereAbout 2 km east of the town of Isaccea; Dinogetia is about 30 km away and Halmyris about 62 km

The history of Noviodunum

Noviodunum, a name of Celtic origin, stood at a crossing of the lower Danube long before the Romans. According to the sources, King Darius of Persia built a bridge of boats here in 514 BC to cross over and fight the Scythians, and the Greeks of the Black Sea cities kept a trading post on the spot. Ancient and Byzantine authors such as Ptolemy, Ammianus Marcellinus and Procopius mention it, a sign of its strategic and economic weight.

The place passed under Roman control with the annexation of Thrace in 46 AD and was attached to the province of Moesia. From there the Romans could watch the whole stretch of the Moesian Limes along this part of the Danube; on the opposite bank the fort of Aliobrix guarded a ford. Under Domitian, and again after Trajan conquered Dacia, Noviodunum became the main port of the Classis Flavia Moesica, the Roman fleet on the lower Danube, and a military centre of the region. Detachments of the Legio V Macedonica were stationed here until at least the reign of Marcus Aurelius, followed by detachments of the Legio I Italica. The civil settlement became a municipium in the late 2nd century.

The city was probably destroyed in the second half of the 3rd century, in the time of heavy invasions by Goths and Heruli. Under Diocletian the Legio I Iovia was created and based here, and after 324 Constantine the Great rebuilt the fortress and placed it under the Dux Scythiae. The imperial road from Marcianopolis ended at Noviodunum. In 369 the emperor Valens crossed the Danube from here and defeated Athanaric and the Tervingi in the Battle of Noviodunum, taking the title Gothicus Maximus. Between 434 and 441 the Huns held the city and its naval base, before it returned to Roman rule and became part of the Byzantine Empire, where it survived until the 7th century.

Before the Tatar invasion of 1241 Noviodunum had become a true Byzantine town, but from the late 13th century the inhabited area shrank back towards the fortress, where life continued until the Ottoman conquest of 1420. The name Noviodunum disappeared and the medieval maps give Isaccea instead. Excavations have uncovered a walled area of about 9 hectares divided into two enclosures: one, from at least before the 4th century, held the headquarters of the Danube fleet, the other is the walled city of the late 2nd century. In the 1990s three towers of the southern curtain wall were revealed: a fan-shaped corner tower, a U-shaped tower and the Large Tower, one of the largest ever built by the Romans. The curtain connecting them is almost 3 m wide and runs for 80 m.

Curiosities about Noviodunum

According to the sources, the Persian king Darius built a bridge of boats at Noviodunum in 514 BC to cross over to fight the Scythians.
The Large Tower of the southern wall is described as one of the largest towers the Romans ever built.
Noviodunum was the headquarters of the Classis Flavia Moesica, the Roman Danube fleet, and later of the Legio I Iovia.
In 369 the emperor Valens crossed the Danube from Noviodunum, won the battle against Athanaric and took the title Gothicus Maximus.
The name Noviodunum is of Celtic origin, and over the centuries it gave way to the name Isaccea.
A large burial mound known as Kurgan-Vizir and many funerary mounds of the Roman cemetery lie on the plateau to the south-west, along ancient roads.

Tours near Castrum Noviodunum

Experiences in the area that you can book online with Viator:

GROUP Guided Day Trip to the Danube Delta, Tulcea - Letea

★ 4.8 (102 reviews) · 9 h

See details ›

Guided Birdwatching day trip to the Danube Delta - private program

★ 5 (28 reviews) · 6 h

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Danube Delta Tour from Tulcea to Mila 23, Letea Forest and Sulina

★ 4.7 (23 reviews) · 10 h

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Danube Delta PRIVATE boat trip to Letea Forest (guided tour)

★ 4.8 (16 reviews) · 9 h

See details ›

Visiting Noviodunum: what to see

The main sights are the three towers of the southern curtain wall, a fan-shaped corner tower, a U-shaped tower and the Large Tower, linked by a wall almost 3 m thick.
The enclosed area of about 9 hectares is divided into two parts, the headquarters of the Danube fleet and the walled city, and three huge earth ramparts surround it.
The site lies on the Danube about 2 km east of Isaccea; Dinogetia is about 30 km away, the Galați TV Tower about 39 km and Halmyris about 62 km.
The sources give no details on facilities or access, so check the current opening hours and conditions before you go.

Opening hours, access and conditions can change. Check before you go.

Map: where Castrum Noviodunum is

Map: © OpenStreetMap contributors

Photos of Castrum Noviodunum

Ruins of the Roman fortress of Noviodunum near Isaccea, first view — Photo: Mixolidic, CC BY-SA 3.0, via Wikimedia Commons

Ruins of the Roman fortress of Noviodunum near Isaccea, second view — Photo: Mixolidic, CC BY-SA 3.0, via Wikimedia Commons

Information panel at the site of Noviodunum — Photo: Unknown authorUnknown author, public domain, via Wikimedia Commons

The archaeological site of Noviodunum near Isaccea — Photo: Badib1900, CC BY-SA 3.0 ro, via Wikimedia Commons

Questions

What is Castrum Noviodunum?

A Roman fortress and city on the lower Danube near Isaccea, the headquarters of the Roman Danube fleet and later of the Legio I Iovia.

Where is Castrum Noviodunum?

On the bank of the Danube, about 2 km east of Isaccea in Tulcea County, Romania.

What role did Noviodunum play for the Romans?

It was a key point of the Moesian Limes on the Danube, the main port of the fleet Classis Flavia Moesica and a military centre, with the imperial road from Marcianopolis ending here.

What can you see at Noviodunum?

Excavated towers of the southern wall, including the Large Tower, one of the largest the Romans ever built, plus earth ramparts and the outline of an area of about 9 hectares.

What happened at Noviodunum in 369?

Emperor Valens crossed the Danube from here and defeated Athanaric and the Tervingi, then took the title Gothicus Maximus.

What else is near Noviodunum?

Dinogetia is about 30 km away, the Galați TV Tower about 39 km, Halmyris about 62 km and Argamum about 67 km.