Tabriz contains many historical monuments, representing Iran's architectural transition throughout its deep history. Most of Tabriz's preserved historical sites belong to Ilkhanid, Safavid and Qajar. Among these sites is the grand Bazaar of Tabriz, which is designated a World Heritage Site. From the early modern era, Tabriz was pivotal in the development, movement and economy of its three neighboring regions; namely the Caucasus, Eastern Anatolia and Central Iran. In modern era city played a vital role in the history of Iran. As the country's closest hub to Europe, many aspects of early modernisation in Iran began in Tabriz. Prior to forced ceding of the Qajar dynasty's Caucasian territories to Imperial Russia, following two Russo-Persian Wars in the first half of the 19th century, Tabriz was at the forefront of Iranian rule over its Caucasian territories. Until 1925, the city was the traditional residence of the Qajar crown princes.