In one city in this Indian state, the Delhi gate is one entrance to a fort built from red sandstone.
One city in this state contains the Fatehpur Sikri, which was the capital for a mere two years. That city also contains the Ram Bagh, one of the oldest Mughal Gardens. Another city in this state was the site of Buddha's first sermon and is the oldest city in its country. In one city in this Indian state, the Delhi gate is one entrance to a fort built from red sandstone. This state's capital is considered to be the center of (*) Shiism in India, and it also contains Varanasi. One city in this state contains a structure with four minarets surrounding a domed tomb. In 2000, its Himalayan portion split off. Its capital is at Lucknow and the Red Fort and Taj Mahal can be found in its city of Agra. For 10 points, name this most populous India state.
One city in this state contains the Fatehpur Sikri, which was the capital for a mere two years.
Uttar Pradesh [prompt on U.P.]