Our eyes and our mind are absolutely satiated with the wonders that we have seen; the first are weary with objects so gigantic and extraordinary, and the latter has been so much on the stretch, being crowded and overwhelmed with ideas so overpowering and various, that we ever despair of forming any calm judgment upon them.

Looking back at five thousand years of Indian History we witness thousands of monuments across the country from north to south and east to west we have monuments belonging to Hindus, Buddhists, Muslims and Christians for example if you are talking about Delhi in Delhi alone we have 2200 monuments alone. 

In India department of Archeological survey of India takes care of all monuments in India. 

Some of the Monuments of India are
Taj Mahal (Agra)
Konark Sun Temple (Orissa)  
Mahabalipuram Temples (Chennai)
Jaislmer Fort (Rajasthan)
Hemis Gompa (Ladakha)
Mehrangarh Fort (Jodhpur)
Victoria Memorial (Calcutta)
Sarnath (Varanasi U.P)
Qutab minar (Delhi)
Meenakshi Temple (Tamil Nadu)  
Jama- Masjid (Delhi) 
Ajanta Ellora (Maharshtra) 
Red Fort (Delhi) 
Udaipur Palace (Udaipur) 
Golden Temple (Amrtisar) 
Khajuraho Temple 
Sanchi Stupa (Bhopal) 
Charminar (Hyderabad) 
Nalanda (Bihar)