Rohtas Fort was built by Sher Shah Suri, the most illustrious Afghan General & King in history. Construction work on the Rohtas fort began in about 1541 A.D and was finished 10 years later after Sher Shah’s death. A stupendous achievement in such a short time. Qila Rohtas or the Rohtas Fort is an exceptional example of early Muslim military architecture in Central and South Asia because it was built essentially for military purpose. A strong fortified complex and a strategic site about 16 kilometers north-west of the city of Jhelum. The gigantic fort is founded on steep rocks jutting into the river Kahan, its ramparts protected on the west and north sides by the river and by high hills on its east and south. The fort is about two-and-a-half miles in circumferences, within the huge terraced rampart walls with robust bastions with 68 towers and 12 monumental gate ways. Since, it was never taken by assault, therefore, survives intact to the present day. The Rohtas Fort is now a protected monument under the Antiquities Act 1975. The fort was inscribed in the World Heritage List, by UNESCO, in 1997.

Wikipedia, Rohtas Fort
UNESCO World Heritage Centre Web page.
Rohtas Conservation page on the Himalayan Wildlife Foundation website
The official website of Rohtas Fort