Solution:The Horse-Shoe arch was first introduced in the Alai Darwaja. It was built by Alauddin Khalji.Alai Darwaza is the southern gateway of the Quwwat-ul-Islam Mosque in the Qutb complex in Delhi, India.
It is built by Sultan Alauddin Khalji in 1311 and made of red sandstone.
It is a square domed gatehouse with arched entrances and houses a single chamber.
It is made up of a single hall whose interior part measures 34.5 feet and the exterior part measures 56.5 feet.
The height of the dome is 47 feet (14 m). It is the first true dome built in India.
In the year 1993, it is considered as a World Heritage site.