Ostrovica Fortress
Kulen Vakuf · Una valley
Martin Brod · Una and Unac · Late medieval
Rmanj Fortress
Rmanj at Martin Brod is a ruined fortress near the Una–Unac confluence, documented in 1431.
- Location
- Martin Brod · Una and Unac
- Local name
- Stari grad Rmanj
- Historical period
- Late medieval
Rmanj fortress was raised near the meeting of the Unac and Una in the late fourteenth or early fifteenth century. The cantonal heritage institute records its first mention in 1431. The surrounding defenses are reduced to foundations, while a round tower survives to approximately ten metres. The nearby Orthodox monastery is a separate monument; this atlas anchor is centered on the actual defensive tower.
Explore the 3D modelHistory and context
More than a military outpost
The heritage institute records King Sigismund pledging Rmanj to Nikola Frankopan in 1431. A judge and a community of townspeople are mentioned in 1451. These references suggest civic organisation alongside the fortress, rather than soldiers alone.
The surviving round tower
A 1504 reference called for repairs and stronger defences. Ottoman control followed in 1524, but the institute leaves the date of destruction unresolved. The round tower preserves vaulted divisions between levels; the surrounding walls are largely reduced to foundations.
A noblewoman's temporary residence
Rmanj’s history includes a domestic episode as well as pledges and garrisons. The heritage institute records that Anžu Frankopan’s widow stayed here for a time in 1436 and used the title associated with Rmanj. This makes the fortress part of the geography of a noble family's household, not simply a watchpoint above the rivers. The brief reference does not reveal the arrangement of her rooms or possessions. It does, however, provide a human connection that the surviving round tower alone cannot explain.
Through the centuries
1431
First historical mention recorded by the heritage institute.
1524
Fortress falls under Ottoman control.
Surviving remains
Round tower remains above the lost defensive circuit.
Architecture & evidence
Round defensive tower
The cantonal heritage institute describes a surviving round tower about ten metres high. Its diameter follows the mapped OSM footprint; wall thickness and crown are estimated.
Tower interior
The source records vaulted separation between former levels. Exact vault geometry is unverified, so this model leaves the shell open instead of inventing interior rooms.
Lost defensive circuit
The surrounding castle walls are reported reduced to foundations. Their undocumented alignments are omitted; the river confluence remains visible through mapped scenery.
Plan your visit
The ruin lies in Martin Brod near the confluence; seek local advice on the approach and avoid climbing fragile masonry.
Get directionsHistorical sources
- USK heritage protection institute · Rmanj architecture and history
- OpenStreetMap · mapped ruin, © contributors / ODbL
- Wikimedia Commons · Rmanj Fortress
How to read this history
A first written mention is not necessarily a construction date. Fortresses were often altered over several centuries. Sections link to their supporting references; the 3D model is an interpretation, not evidence of every historical phase.