New Delhi is famously the site of seven historical capitals, and currently the eighth. This results in the city being full of monuments from many eras worth seeing.
For example, Humayum's tomb, which is the inspiration for Taj Mahal in Agra, or the Qutub Minar, the world's largest brick minaret visible from the workshop venue.
Near Humayun's tomb is the newly restored Sundar Nursery, a sprawling park full of monuments in different states of restoration, and picnickers and cafe visitors near the ponds and the nature parks. They also have a farmer's market on the weekends.
Down Lodhi Road is Lodhi Garden, a vast park full of monuments and tombs.
Near Lodhi Road one finds Dilli Haat, a market with handicrafts from all over India. All Indian states are also represented here with a food stall serving signature dishes. Across the road from Dilli Haat is the INA Market which will fill all your spice buying needs.
Near IIT Delhi one finds Hauz Khas village, an area full of bars, art studios and restaurants, near a 14th century Mughal Madrasa with attached water reservoir in Deer Park (which also has many deers).
The currrent capital was built by the Brittish in the 20th century. The famous Raj Path houses the parliament, many national museums and India Gate.
The famous Delhi shopping areas are Janpath with its (all year) Christmas Market. On Janpath one finds the multi storey handicraft shop Cottage Emproium (careful when asking for directions, your autodriver may take you to any other so called cottage emporium for a commission).
Next to Janpath is Connaught Place with its branded stores and large restaurants.
Also, in this area is the unmissable stepwell Agrasen ki Baoli, a hidden gem!
No trip to Delhi is complete without exploring the sprawling alleys of Old Delhi. It is easiest accessible via the newly renovated (and car free!) Chandni Chowk Road. This leads all the way to the Red Fort. While in Old Delhi, one must try the famous Kebabs (for example at Karim's), the Aloo Poori (only available in the mornings) and Parathas in Paranthi Wali Gali. One of Delhi's most famous building is the 17th century red sandstone Mughal Mosque Jama Masjid.
