Gavmishan Bridge

The historic Gavmishan Bridge, located in Darreh Shahr County in Ilam Province, is one of the engineering and architectural masterpieces of the Sasanian era. It was built over the Seymareh River, downstream of its confluence with the Kashkan River. The bridge is about 175 meters long, with a roadway 8.20 meters wide, and has six arched openings. One of them, with a span of more than 33 meters, is considered the widest arch opening in ancient architecture anywhere in the world. The monument was registered on 3 Esfand 1377 (Solar Hijri) as a national heritage site of Iran under registration number 2222, and is regarded as a symbol of the region's historical engineering.

Gavmishan Bridge has six arched spans, and the size of its piers ranges from about 2.5 meters to 25 meters. Its main span, 33.7 meters wide, is regarded as the largest known arch in ancient Iranian architecture, and even in the world. The structure is built of stone, brick and mortar, and its piers and arches are a distinctive example of Sasanian architecture. Traces of restoration in some sections show that the bridge was also rebuilt during the Safavid and Qajar periods. In addition, steps have been built into some of the passageways, which suggests that caravan travelers once used these spaces as temporary shelter during their journeys.

To reach Gavmishan Bridge, travelers can drive about 120 kilometers from the city of Ilam toward Pol-e Dokhtar, then cover a further 20 to 30 kilometers to reach Darreh Shahr County. The route is largely clear and has signposts. The best time to visit this historic monument is spring, when the weather in the region is mild and the nature around the bridge is pleasant for walking and exploring. Practicing responsible nature tourism is also essential to preserve the authenticity and unspoiled character of this valuable heritage site. This means avoiding damage to vegetation and not leaving litter, especially along the riverbank.