quality:corruption, linguistic:paraphrasing
Architecture

The oldest surviving architectural monuments of Tehran are from the Qajar and Pahlavi eras. In Greater Tehran, monuments dating back to the Seljuk era remain as well; notably the Toqrol Tower in Ray. Rashkan Castle, dating back to the ancient Parthian Empire, of which some artifacts are housed at the National Museum; and the Bahram fire temple, which remains since the Sassanian Empire.

Tehran only had a small population until the late 18th century but began to take a more considerable role in Iranian society after it was chosen as the capital city. Despite the regular occurrence of earthquakes during the Qajar period and after, some historic buildings remain from that era.

Tehran is Iran's primate city, and is considered to have the most modernized infrastructure in the country. However, the gentrification of old neighbourhoods and the demolition of buildings of cultural significance have caused concerns.

Previously a low-rise city due to seismic activity in the region, modern high-rise developments in Tehran have been built in recent decades in order to service its growing population. There have been no major quakes in Tehran since 1830.

Tehran International Tower is the tallest skyscraper in Iran. It is 54-stories tall and located in the northern district of Yusef Abad.

The Azadi Tower, a memorial built under the reign of the Pahlavi dynasty, has long been the most famous symbol of Tehran. Originally constructed in commemoration of the 2,500th year of the foundation of the Imperial State of Iran, it combines elements of the architecture of the Achaemenid and Sassanid eras with post-classical Iranian architecture. The Milad Tower, which is the sixth tallest tower and the 24th-tallest freestanding structure in the world, is the city's other famous landmark tower. Leila Araghian 's Tabiat Bridge, the largest pedestrian overpass in Tehran, was completed in 2014 and is also considered a landmark.