Toghrol Tower (Persian: برج طغرل, [Tuğrul Tower]) is the famous circular tower in the heart of Shahr-e Rey city, one of the valuable monuments of the ancient land of Rey. These days, with the growing city, it is almost close to the city of Tehran. The tower still retains its splendor and magnificence after more than 700 years. Toghrol Tower is the tomb of many scientists and wise people of the Seljuk era (1037-1194).
The interior design of the Toghrol Tower is cylindrical, and the exterior consists of 24 vertical angles. On the north and south sides of the tower, two entrances with Razi style architecture (a form of Iranian architecture) have been built. The hollow structure of the tower has contributed a lot to the strength of the building.
Due to the severe earthquakes in this area, a deep and dense foundation has prevented the collapse. The architect of the tower has installed several holes on the walls to flow the air caused prevention moisture from leaking into the walls. The walls of the tower are also acoustic. The tower used to have a roof that amplified these echoes, but today it has been ruined.
In addition, Toghrol Tower also has a sundial function. There are 24 vertical angles around the exterior of the tower. At the top of each angle, there are four and a half shapes in a circle, representing a quarter of an hour. Also, there are six rectangles, each shows 10 minutes, and the narrower grooves indicate the minutes. It is worth mentioning that the two eastern and western downspouts of the tower show 3 and 9 o'clock, and the north and south doors of the tower also show 6 and 12 o'clock.
Another use for the Toghrol tower was to light a fire on top of the tower, giving it the landmark function that guides those coming towards Rey from Khorasan on the Silk Road.