Rajpath – This is a main parade route that leads to the President's residence (Rashtrapati Bhavan). Don't miss the splendid India Gate, and the many grassy lawns. Especially nice in the evenings and at night when the buildings are lit and the vendors come out to supply the many picnicking families.
Rajghat Memorial of Mahatma Gandhi - check for closure dates/security checks around national holidays/gandhiji's death anniversary (30th Jan).
Lodhi Estate
Nehru House 'Teen Murti Bhavan'. This is the house of the first Prime Minister of India. Remarkably well preserved with most of paraphernalia intact. Was used by the Commander-in-chief of the Indian Army before Indian Independence. Free entrance.
India Gate. This monument has been built as a memorial for the Indian soldiers who died in World War I. There is also a fire ("eternal flame") burning for all fallen Indian soldiers.