Eskandar Prison is an ancient domed structure apparently known by this name as a result of a reference in a Hafez poem. The complex contains a deep, circular, brick-lined pit almost 10 meters in diameter resembling an ancient dungeon found at the heart of the old. There is also a well and some nooks in the courtyard. It is alleged by some to have been built by Alexander to hold his captives during his conquest of Persia and alleged by others to have been built by the Persians to hold Alexander himself. Whatever the true story, the complete complex itself is almost certainly a later construction.
The dome of Eskandar Prison is made of raw clay and is decorated with plaster works and golden and azure watercolor. The noteworthy architectural features of the dome are traceable in other domes dating to the Mongolian period in Iran. Each side of the domed tower is almost 9 meters long and it rises almost 18 meters tall.
There is little left of the inscriptions inside the dome but from what remains it appears to be kufic writings. The material used in much of the building is clay, however, it has been restored with bricks in the past few decades. Some steep stairs lead the way down into the dungeon although nowadays it is a beautiful room decorated with tables and red carpets and serves is a tea house.