Robat Sharaf, or Sharaf Caravanserai, is an important historical place that dates back to the late Seljuk era. It is located in the eastern part of the Red Road in Khorasan Razavi province. It was completed in 1154, under the reign of Sultan Sanjar. The founder of the building is Sharafadin Abutaher Ben Sa’dadin Ala al-Qomi. He was one of the rulers of the city of Marv and once the chancellor in the court of Sutan Sanjar.
Rabat Sharaf was 4863 meters in size and composed of two yards, each with four porches. The entrance was designed with blocks. The building has six towers from outside. There used to be three plastered vaults in the caravanserai but only two of them exist right now. The building is decorated with different types of blocks, plastered layers and mixed forms of block and plaster, making it one of the masterpieces of the twelfth and the thirteenth centuries. A precious collection of metal dishes from the Seljuk era, a set of commands from the Safavid era, coins, pots and unique crimson wares were found in one of the rooms of the caravanserai as restoration process was underway. There was a plaster inscription in Sols calligraphy under the vault that was found there. Many researchers call Robat Sharaf a museum of the art of architecture.