Chandni Chowk (Hindi: चांदनी चौक, Urdu: چاندنی چوک), originally meaning "moonlit square" or "moonlit market", is one of the oldest and busiest markets in Old Delhi, now in central north Delhi, India. Built in the 17th century by the Mughal emperor of India Shah Jahan, and designed by his daughter Jahan Ara, the market was once divided by canals (now closed) to reflect moonlight, and it remains one of India's largest wholesale markets.
Procession of King Edward VII and Queen Alexandra as Emperor and Empress of India, 1903 Delhi Durbar
The history of Chandni Chowk dates back to the foundation of the capital city of Shahjahanabad when the Mughal emperor Shah Jahan established the Red Fort on the banks of the River Yamuna beside his newly founded capital.
Chandni Chowk, or the Moonlight Square, was designed and established by Princess Jahanara, Shah Jahan’s favourite daughter, in 1650 CE. The bazaar, which was shaped as a square, was given further elegance by the presence of a pool in the centre of the complex, which shimmered in the moonlight, a feature which was perhaps responsible for the nomenclature of the marketplace. The shops of the complex were originally built in a half-moon shape, a pattern, which, however, is lost today. The bazaar was in the time of Shah Jahan famous for its silver merchants, which could also have an important role to play in the nomenclature of the Chandni Chowk as silver is referred to as Chandi in Hindi, a word which could have been slightly deformed to form Chandni Chowk.
Chandni Chowk was once the grandest of the markets in India. The Mughal imperial processions used to pass through Chandni Chowk. The tradition was continued when Delhi Durbar was held in 1903. Delhi Town Hall was built in 1863 by the British.
Chandni Chowk runs through the middle of the walled city, from the Lahori Gate of the Red Fort to Fatehpuri Masjid. Originally, a canal ran through the middle of the street as a part of the water supply scheme. It was initially divided into three sections:
Lahori Gate to Chowk Kotwali (near Gurdwara Shish Ganj): This section closest to the imperial residence, was called Urdu Bazar, i.e., the encampment market. The language Urdu got its name from this encampment. Ghalib noted the destruction of this market during the disturbances of the Indian Rebellion of 1857 and its aftermath.
Chowk Kotwali to Chandni Chowk: The term Chandni Chowk originally referred to the square that had a reflecting pool. It was replaced by a clock-tower (Ghantaghar) that was damaged and demolished in the 1960s. This section was originally called Johri Bazar.
Even though today Chandni Chowk appears choked with congestion, it retains its historical character. The following terms are generally used to describe the buildings and the streets:
Haveli: a mansion. A normal haveli would have a big courtyard (atrium) surrounded on four sides by spacious rooms and often another walled courtyard around the exterior as well. One of the largest preserved havelis in the area is the Chunnamal haveli.
Kucha: a zone with houses whose owners shared some common attribute, usually their occupation. Hence the names Maliwara, the gardeners' neighbourhood and Ballimaran, the oarsmen’s neighbourhood.
Katra: refers to a separate wing of tradesmen and craftsmen belonging to the same trade. They usually lived and worked together. It is a system similar to the guild housing in Amsterdam.
It is a famous market known all over India. Google India helps Delhi's iconic Chandni Chowk market go online. They approached each of 2500 stores and even have opened common website for all the shops.
On both sides of the wide Chandni Chowk are historical residential areas served by narrow lanes (gali).
With the most famous mosque of Delhi, Jama Masjid, built in 1650 in the vicinity, it is an unusual street that has several famous religious shrines, belonging to coexisting religions, lending the street a genuine cultural harmony. Starting from the Red Fort, the street has:
Sri Digambar Jain Lal Mandir, established in 1656 with a bird hospital established in 1929. There is a Naya Mandir built in 1807 nearby in Dharampura, which was the first temple with a shikhar permitted.
Hindu Gauri Shankar Temple built by a Maratha general Appa Gandgadhar in 1761.
MuslimSunehri Masjid built in 1721 by Roshan-ud-Daula Zafar Khan in the reign of Mohammad Shah. The Persian invader Nadir Shah spent several hours on the top of the mosque on 11 March 1739 to observe the Katl-e-Aam (the killing of everyone in sight) that he had ordered which resulted in 30,000 deaths.
Naughara mansions in Kinari Bazaar, 18th century Jain mansions.
Khazanchi haveli, khajanchi were the accountants of Shah Jahan. There is a street named after them called "Gali Khajanchi", a long underground tunnel connects the haveli and the Red Fort, so that money could be transferred safely.
Haveli Naharwali, Kucha Sadullah Khan, where Pervez Musharraf, former president of Pakistan was born.
Chandni Chowk's speciality is the variety of its markets and their Indian-ness: from authentic Indian food, delicacies and sweets of more than 1,000 kinds, to sarees with chikan and zari work. There are many narrow lanes with shops selling books, clothing, shoes and leather goods, electronic and consumer goods and whatnot. The area, even more so than the rest of the city, is very congested. This is also a good place for window shopping. It is the location of the original Haldiram's. A particular local delicacy are the jalebis, which are fried in pure ghee (clarified butter).
As one moves from part of Chndni Chowk to the other, the lanes and bylanes house the biggest wholesale markets of Delhi.
Cloth Market, a market for all the needs of the home furnishing fabrics. One can get readymade items as well as customised services for decorating the houses.
Nai Sarak,the wholesale market of stationary, books and decorative materials. It house the stores of Plastic folders like SOLO, Shipra  and many other leading brands. Nai Sarak is also a market for buying exquisite bridal Saris and Lehengas. DIVASA by Devta Apparels Pvt. Ltd jogiwara Arun Sarees and Nandlal Silk Mills 
Lal Kuan is the wholesale market for hardware as well as hotel kitchen equipments. It is adjacent to Tilak Market which is wholesale place for industrial chemicals.
Dariba is associated with market of Silver and Gold Jewellery. The popular Jewellery stores are Hare ram Hare Krishna and MM Jewellers
Restaurants and eateries
Food shop on Khari Baoli Road
Chandni Chowk is home to several famous restaurants/confectioners (halwais).
Gianiji ka Falooda, famous for Rabri Falooda, established around 1947.
Paranthewali Gali with paratha shops from 1875–1886.
Meghraj and Sons, since the 1950s (?)
Chainaram, established in 1948
Annapurna Bhandar is popular for Bengali sweets in Old Delhi. The most loved sweets served are Rasgulla, Plain Sandesh, Gur Sandesh, Ras Malai, Samosa, Dilbahar Recipes, Kadambari, Kheer Kadam, Kachagola, and Mishti Doi.
Depiction in media
Chandni Chowk was featured in the 2001 Bollywood film Kabhi Khushi Kabhie Gham where the leading lady Anjali (Kajol) and her sister Pooja (Kareena Kapoor) lived. Though portrayed as a neighbourhood populated by a lower-class population, Chandni Chowk is shown to be a rich, cultural hub.