Major buildings within include:
Chatta Chowk, (Covered Bazaar). True to the name, this is a covered bazaar between the gate and the fort itself, now filled with souvenir hawkers.
Diwan-i-Am, (Hall of Public Audience). This building separates the outer court from the inner court, and has a marble platform for the emperor's throne.
Hayat Baksh Bagh, (Life-Bestowing Gardens). Once a grand garden of full of fountains and streams, now sadly all dry — only dry channels and acres of green grass remain.
Diwan-i-Khas, (Hall of Private Audience). Built completely of marble, this is where the emperor received special visitors.
Khas Mahal, (Private Palace), The Emperor's main residence. The octagonal Mussaman Burj tower looks out toward the Yamuna River, and is where the Emperor used to appear before the public for each morning.
Rang Mahal, (Colour Palace). The residence of the Sultan's main wife.
Mumtaz Mahal, (Jewel Palace). Contained six apartments for the Sultan's harem.
Daawat Khana, A minor palace at the northmost end of the Fort, this was originally the residence of a prince, but it was converted into a tea house by the British, a function it continues today.
Swatantra Sangrama Sangrahalaya, (Museum of the Independence Movement). To the left after the Chatta Chowk, this is a reasonably well-presented museum on the history of independence activism in India, starting from the Mutiny of 1857 all the way to Gandhi.
Humayun's Tombis one of Delhi's three UNESCO World Heritage Sites. The tomb is in large, immaculately maintained gardens in the Persian Char Bagh (four corners) style that were thoroughly renovated in 2003 with the Aga Khan's help and are consequently probably the best in Delhi. As you enter the complex, the first major structure on your right is the bulbous, octagonal tomb of Iza Khan, a court noble who built it in his own lifetime, some 20 years before Humayun's tomb. As you pass through the first gate, you will glimpse the dome of the tomb and enter a floral path leading to the second (West) gate, which now acts as the entrance to the giant central garden.
The centerpiece is the eponymous tomb of Humayun, the second Mughal emperor. Built starting in 1562, it was the first major Mughal structure in the city and has been described as a predecessor or prototype of Agra's Taj Mahal. The structures are, indeed, stylistically similar, although Humayun's Tomb is built from red sandstone, not white marble, and was built by a wife grieving for her husband, not the other way around. You can climb up to the second level (the stairs on the west side are very steep, those on the south side less so), and on the south side you will find the entrance into the main crypt where Humayun is buried.
Before you leave, be sure to visit the South Gate, the original royal entrance, from where you can get picture-postcard views without too many tourists in the way. In the southeast corner is the Babur's Tomb, also built in the same style. Historians believe that Humayun's father, Babur is buried in this picturesque tomb made of red and grey sandstone.
This complex in Mehrauli, houses structures dating from the Slave Dynasty (1206-1290) and is designated as a UNESCO World Heritage Site.
Qutub Minar, The most famous structure on grounds, this 72.5 m minaret was the tallest "skyscraper" in the world when built (1193-1368) - it was constructed on the orders of Qutb-ud-din Aybak.
Quwwat-ul-Islam Mosque, Delhi's first and grandest mosque, now mostly in ruins, but many parts of the complex are still standing and the sandstone decorations are still impressive. Check out the extraordinarily ornate carvings near the tomb of Iltutmish on the west side of the complex.
Iron Pillar, iIn the centre of the mosque. True to its name, this is a 7 m iron pillar erected in 400 AD by Chandragupta II Vikramaditya, also known as "he, by the breezes of whose prowess the southern ocean is even still perfumed" according to the inscription carved on the base. Alas, Chandragupta II's perfume has long since faded, but to the amazement of metallurgists everywhere, his pillar is still going strong, after 1,600 years.
Ala-i-Minar, Ala-ud-din-Khilji set out to build a tower twice as high as the Qutub Minar, but died after a mere 24.5m was complete. The first story stands to this day.
Ala-i-Darwaza, This square, domed building once acted as the entrance to the mosque, but is now tucked away behind the minar. Inlaid marble decorations and latticed stone screens.
Tomb of Imam Zamin, Outside the main complex, next to the Ala-i-Darzawa, this octagonal tomb commemorates a Turkestani iman who was based in the mosque during the reign of Sikandar Lodi.
Gandhi Smriti. This estate is the site of Mahatma Gandhi's martyrdom. Includes a museum celebrating his life and the room he lived in during his final days.
India Habitat Centre. This center though not a museum in the strictest sense of the word, is most noted for its ever-changing art exhibits, plays and films, as well as an international selection of food items in its food court.
International Doll's Museum. A museum of dolls from all over the country. You get to see the costumes and art from all over India, as well as some nice crafts.
National Museum. The layout here is a labyrinthine and the presentation won't win any awards, but the collection is unparalleled and contains some true masterpieces. The section on the Indus Valley Culture and the one on Buddhist Heritage is most informative. The museum also showcases the arts and handicrafts from different regions of India.
National Science Centre. Although the name is too grand, the museum is definitely a must see for science enthusiasts, especially those who are young.
National Railway Museum. houses a collection of Indian trains from the past to the present - a worthwhile look into India's proud railway heritage. The collection includes carriages belonging to Indian potentates and British viceroys. Children can ride the small train that circumnavigates the museum.
Nehru Memorial Museum (Teen Murti Bhavan). Former residence of India's first prime minister, Jawaharlal Nehru, now a museum of his life. Was used by the Commander-in-chief of the Indian Army before Indian Independence. Includes a Planetarium.
Tibet House. Established by HH Dalai Lama with the aim of preserving the cultural heritage of Tibet. There is a museum, exhibition space and library.
Rajpath, This is a main parade route that leads from Rashtrapati Bhavan (the President's residence) to India Gate, with many grassy lawns along the way. Especially nice in the evenings and at night when the buildings are lit and the vendors come out to supply the many picnicking families.
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.
Jantar Mantar. One of five astronomical observatories commissioned by Sawai Jain Singh II of Jaipur during the 18th century. The odd structures inside are actually enormous scientific instruments for measuring the movement of celestial bodies
Raj Ghat. Memorial to Mahatma Gandhi at the site of his cremation.
Purana Qila (Old Fort). Ruins of the 16th century city of Shergarh, this complex sits on top of what is believed to be the site of Indraprastha, the capital of the Pandavas in the Mahabharata epic.
Tughlaqabad Fort. Massive fortress built by Ghiyasuddin Tughlaq in the 14th century and was the third city of Delhi. The monstrous ruins of this complex are now overrun by hordes of Langur monkeys.
Azaad Hind Gram. A tourist complex dedicated to Netaji (respected leader) Subhash Chandra Bose, a leader in the Indian independence movement.
Bahá'í Lotus Temple. Shaped like a lotus bud with 27 petals, this stunning temple suspended above milky-blue ponds is surely one of the most magnificent monuments ever made from concrete, however there is very little to see inside. The lush park around is well landscaped but mostly off-limits.
Chhattarpur Mandir . Huge & beautiful temple complex with a big surrounding campus - located near Mehrauli area of South Delhi.
Gurudwara Bangla Sahib, is the main gurudwara for the many Sikhs of Delhi. You will need to cover your head (scarves provided for free) and stash your shoes in the shoe storage run by volunteers.
Gurudwara Sis Ganj. An important Sikh place of worship. Built on the spot where their ninth guru, Guru Tegh Bahadur, was beheaded on the orders of the mughal emperor Aurangzeb, it is an oasis of calm in the chaos of Old Delhi's Chandni Chowk. You will need to cover your head (scarves provided for free) and stash your shoes in the shoe storage run by volunteers.
Sacred Heart Cathedral It is the biggest church in terms of structure and also the headquarters of the Delhi Catholic Archdiocese. A must visit to enjoy the beutiful architecture and pristine beuty.
Cathdral Church of Redemption It is the headquarters of the Church of North India, Delhi Diocese. Built by Henry Medd between 1927-1935 it is a fine example of Colonial architecture.
St. Peter's Cathedral Bhai Veer Singh Marg, It is known as the Antioch of the East and is a fine example of Oriental architecture blended with modernity.
ISKCON (Hare Krishna) temple, at East of Kailash – Centre for Krishna Consciousness, it has robotic shows and multimedia presentations, apart from the traditional temple complex. Lively atmosphere and excellent tasting sweets - and the delicious Govinda's restaurant is on site.
Jama Masjid The largest mosque in India and a must-see while in Delhi.
Lakshmi Narayan Temple or popularly known as Birla Mandir. It is a big impressive Hindu temple complex.
Swaminarayan Akshardham Temple .Completed in 2005 by the socio-spiritual organization BAPS, no expense has been spared in decorating this large and elaborate temple carved of red sandstone. The central monument, built without any steel, houses an 11-ft golden statue of the founder of the Swaminarayan faith, Bhagwan Swaminarayan.
Sai Baba Temple . Although there are many Shirdi Sai Baba Temples in and around Delhi, the one located at Lodhi Road is the oldest.