Qutb Mosque, first one built after earliest Muslim invasion in India

India, New Delhi, Qutb Minar and Quwwat-ul-Islam Mosque winterlight.photoshelter.com
Quwwat-ul-Islam, an ancient mosque at the base of an islamic victory tower. Delhi, India www.123rf.com
Quwwat-ul-Islam, also known as the Qutb Mosque  (meaning 'Might of Islam')  or the Great Mosque of Delhi was the first to be built in Delhi after the Islamic incursions into India. It is a unique example of the fusion of Hindu and Islamic art.  Built by Qutb-ud-din-Aibak, the founder of Slave or Mamluk dynasty on the model Adhai-Din-ka-Jhonpra in Ajmer, it was constructed upon demolishing the Jain temples and the Sanskrit learning center that had existed for a long time.. Quwwat-ul-Islam was constructed during the reign of Mohammad Ghori  after  his  accession  to the throne of Delhi.  Qutb-ud-Din Aibak  subsequently named this mosque as 'Jami Masjid' or 'Friday Masjid'. 
Detail of 14th century Alai Darwarza gateway to Quwat Ul Islam Mosque in Qutb Minar complex. www.alamy.com
The construction work of this Masjid began in 1193 A.D and was completed in the year 1197 A.D. Made of red and yellow sand stone, it stands out majestically tall within the Qutb complex. Along with is structure also came up the famous tall structure the Qutub Minar an important land mark of Delhi.  Records point out that twenty seven pillars, taken from Hindu temples built by the Tomars and King Prithviraj Chauhan were errected to support the Mosque. So is an iron pillar taken from a Vishnu Temple kept  the middle of the prayer hall of the mosque called as the 'pillar of the law'. Later additional arcades were built by Iltutmish, the successor of Qutb-ud-din Aibak,. It was during the time of Alauddin Khilji  in 1300 A.D., the main entrance gate  called 'Alai Darwaza' was built and a court was added on the eastern side of the mosque. There is a tomb of Imam Zamim, the main priest here during Sikander Lodhi's rule..
Quwwat-ul-Islam (the Might of Islam) mosque in Qutb Minar Complex Pillars depict Hindu temple design.. www.alamy.com
 The Mosque which is a good example of Hindu-Islamic architecture is not well  maintained by the authorities and it is losing its old charm and needs urgent restoration. However, the floral designs and the transliterations of the Holy Quran and the graphic symbols remain unaffected.  No other Mosque shows as  much fusion of Indo-Islamic art work, designs and architectural styles as this  place of veneration does, characterized by  Hindu motifs like bells, cows, branches, leaves, on one hand, and   calligraphic carved transcriptions of Quran in the porticoes on the other. The prayer hall is yet another example of fusion of designs from two different cultures. 

This historical mosque is a perfect reminder of the  early Muslim invasion in India from the NW region . On the eastern side of the portico there is a separate prayer space for women and the best time to visit this mosque is from October to March,

Ref:.
http://religions.iloveindia.com/mosques/quwwat-ul-islam.html#sthash.cLfOpusE.dpuf

http://www.orientalarchitecture.com/india/delhi/quwwat.php