Delhi
Explore Delhi's extraordinary layered history through its UNESCO monuments — Red Fort (Mughal masterpiece, 1648), Qutub Minar (72.5 m tall; world's tallest brick minaret, 1193 AD), Humayun's Tomb (prototype of the Taj Mahal), India Gate, Purana Qila, Lodhi Garden's medieval tombs, and the Hauz Khas complex.
A 'Delhi Heritage Walk' with India City Walks or Delhi Heritage Walks guides visits 6–10 sites expertly in one day. The Mehrauli Archaeological Park (free entry) has 80+ medieval monuments in one park.