Sarouyeh was a large library in ancient pre-Islamic Iran. The 10th century chronicler Ahmad ibn Rustah refers to it as "Sarough". The Fars Nameh of Ibn Balkhi calls it Haft Halkeh .
The library, located near where the city of Isfahan is today, is written by some sources to have been from the era of Tahmuras, in ancient Iran. Majmal al-tawarikh also mentions the library.
The book Mahasen Isfahan printed by Abbas Eqbal Ashtiani, gives details of the library and the books it contained from antiquity.
Abbas Milani describes the fortified collection of writings and documents as such:
"Though only a few pages of its vast holdings have survived, we know of its grandeur through the testimony of its contemporaries, who compared it, in terms of the awe it inspired, to the Egyptian pyramids".
Reference: http://en.wikipedia.org/wiki/Sarouyeh