Adhai Din Ka Jhonpra is a remarkable structure of Indo-Islamic architecture said to have been built in two and a half days flat. This mosque was a Sanskrit college in the 12th century but in 1193 AD Mohammad Ghori destroyed the college and built a mosque in its place. It is built on pillars and surprisingly no two pillars are alike.
The distinct pillars-and arched 'Screen' with its ruined minarets make it a splendid architectural masterpiece. The monument has seven arched walls with Islamic calligraphy, though most of it now remains in ruins.
'Adhai Din Ka Jhonpra' literally means 'shed of two-and-a-half days'. As mentioned earlier, a legend states that a part of the mosque was built in two-and-a-half days. Some Sufis claim that the name signifies a human's temporary life on the earth. According to the ASI, the name probably comes from a two-and-a-half-day-long fair that used to be held at the site.
Har Bilas Sarda points out that the name 'Adhai-Din-ka-Jhonpra' is not mentioned in any historical source. Before the 18th century, the mosque was simply known as a 'Masjid' ("mosque"), since it had been the only mosque in Ajmer for centuries.