Like many sites of ancient Romalian forts that line the Tannah Sea, Tel-Iundmare is built upon defensible ruins left by previous civilizations. Unlike many Tannah forts, Tel-Iundmare was important enough to to receive extensive expansion during the Great War, even as its empire and heartland collapsed. The first construction on the site was a tower raised on a hill by an unknown magus, likely of Qhashdea or Hamarettic origin. The site gives effective overwatch on north-south travel on the narrow strip of land on Taschel's eastern shore, but given the lack of suitable deep-water on this side of the island much debate was had on its selection by the magus. One popular theory says it was chosen for mystical reasons, having symbolic alchemical meaning or built upon site of magical energy. Others speculate an even more ancient Oran origin.
Early attempts by the Romalians to dismantle and recycle the tower failed as magic appears to protect the structure from damage. It was instead converted to a lighthouse and signal tower, able to alert Jadyre of incoming ships. Minor fortifications were built around the tower, but the bulk of Romalian expansion came in the form of large concrete piers built out onto the reefs with coastal fortifications and facilities to support them. Though not able to house large cargo vessels, and lacking a fast land route to other Romalian settlements on the island, the dockworks were used to base one of several anti-piracy flotillas that protected Taschel and the nearby High Kingdom of Orises.
During the Great War the piers and other Romalian additions were destroyed, either by enemy forces or by tsunamis that rocked much of the southern Tannah region after the destruction of Nian. The tidal destruction was particularly severe, as coral was strewn across the hill fort and cut a deep gash into the shoulder of nearby Mt. Marion. Strangely these colorful coral deposits have not died but slowly grow on the dry land, and travelers report that at certain lunar times the inland reefs roar with the sound of an invisible wave, an echo of the surge that created it. Some also theorize that the magic of the tower is tied to the thriving of the coral. The tower, even when in Romalian use, was considered either cursed or at least worthy of caution, so the site saw little attention in the 4th Age. Romalian concrete was occasionally recycled as construction filler, but even pirates preferred other hideouts for permanent settlement.
The shore settlement was occupied and partially repaired by Coel-Mahar as a forward operating base to protect Esis.