Soltaniyeh is a historical city located in Zanjan Province, Iran. It is best known for the Soltaniyeh Dome, a UNESCO World Heritage Site, which is one of the largest brick domes in the world. The city was established in the 14th century and served as a significant center during the Ilkhanate period. The Soltaniyeh Dome is an architectural marvel, showcasing intricate tile work and unique design elements. It was built as a mausoleum for Oljaytu, an Ilkhanid ruler, and reflects the artistic and cultural achievements of the time. Today, Soltaniyeh attracts visitors interested in history and architecture.