Ha Noi

Area: 3,323.6 sq. km.
Population: 6,844.1 thousand habitants (2012).
Administrative divisions: 
-12 urban districts: Hoan Kiem, Ba Dinh, Dong Da, Hai Ba Trung, Tay Ho, Thanh Xuan, Cau Giay, Long Bien, Hoang Mai, Ha Dong, Nam Tu Liem, Bac Tu Liem.
- 1 town: Son Tay. 
- 17 rural districts: Dong Anh, Soc Son, Thanh Tri, Gia Lam (Ha Noi); Ba Vi, Chuong My, Dan Phuong, Hoai Duc, My Duc, Phu Xuyen, Phuc Tho, Quoc Oai, Thach That, Thanh Oai. Thuong Tin, Ung Hoa (former Ha Tay province) and Me Linh (a former district of Vinh Phuc province).
Ethnic groups: Viet (Kinh), Hoa, Muong, Tay, Dao...
Ha Noi is the capital of the Socialist Republic of Viet Nam, the center of culture, politics, economy and trade of the whole country.

Geography
Ha Noi is located in the Red River Delta, in the center of North Viet Nam. It is encompassed by Thai Nguyen and Vinh Phuc provines to the north, Ha Nam and Hoa Binh provinces to the south, Bac Giang, Bac Ninh and Hung Yen provinces to the east, Hoa Binh and Phu Tho provinces to the west.

Ha Noi means "the hinterland between the rivers" (Ha: river, Noi: interior). Ha Noi's territory is washed by the Red River (the portion of the Red River embracing Ha Noi is approximately 40km long) and its tributaries, but there are some other rivers flowing through the capital, including Duong, Cau, Ca Lo, Day, Nhue, Tich, To Lich and Kim Nguu.

Climate: Ha Noi is situated in a tropical monsoon zone with two main seasons. During the dry season, which lasts from October to April, it is cold and there is very little rainfall, except from January to March, when the weather is still cold but there is some light rain. The wet season, from May to September, is hot with heavy rains and storms. The average annual temperature is 23.2°C (73.7°F) and the average annual rainfall is 1,800mm. The average temperature in winter is 17.2°C (62.9°F), but can go down to 8°C (46.4°F). The average temperature in summer is 29.2°F (84.6°F), but can reach up to 39°C (102.2°F).

Best time to visit Hanoi
Autumn (around September to November) and Spring (March and April) are two best seasons to visit Hanoi when the weather is pleasant with milder temperatures. In winter, Hanoi is quite cold when the temperatures can fall below 10ºC (50ºF) and getting hotter in the summer averaging around 28-35ºC (82º-95ºF).

Meter taxis and hired cars are easy to find in Hanoi. If you plan an extended visit you might consider renting a bicycle or motorbike.
The north end of Hoan Kiem Lake is Hanoi's "ground zero". Practically all the city’s economical hotels, tourist shops, and cafés catering to visitors are located here. Not only is it the oldest part of the city, it is the busiest and most interesting. Every street is winding, intimate, and shady. At night the lights of storefronts keep the streets lit and animated.
Depending on which guide book you read, this district of Hanoi is variously called the "Old Quarter," the "Ancient Quarter," and "36 streets." It is wedged between the northern shore of Hoan Kiem Lake, the walls of the ancient Citadel, and the levies that protect the city from the Red River. The 36 little streets in the quarter are each named for a commodity once sold by all the businesses on that street. Streets here are named for the medicine, jewelry, fans, copper, horse hair, chicken, and even coffins once sold on them. This explains why the names of some of the longer streets inexplicably change after one or two blocks. As you explore, you will still happen upon entire blocks of tinsmiths, tailors, paper goods merchants, and lacquerware makers.
In the Ancient Quarter the most appealing mode of transportation for those who do not care to enjoy the "36 Streets" on foot is the cyclo. Often they are driven by men wearing pea-green pith helmets that make them look like
soldiers. Settle on the fare in advance (a dollar or less one way). Most drivers will also quote you an hourly rate and will take you to all the obligatory cultural and historical spots

Ha Noi is a sacred land of Viet Nam. In the 3rd century BC, Co Loa (actually belonging to Dong Anh District) was chosen as the capital of the Au Lac Nation of Thuc An Duong Vuong (the King Thuc). Ha Noi later became the core of the resistance movements against the Northern invasions. Located in the middle of the Red River Delta, the town has gradually expanded to become a very populations and rich residential center. At different periods, Ha Noi had been selected as the chief city of Viet Nam under the Northern domination.In the autumn of Canh Tuat lunar years (1010), Ly Thai To, the founder of the Ly Dynasty, decided to transfer the capital from Hoa Lu to Dai La, and so he rebaptized it Thang Long (Soaring Dragon). The year 1010 then became an historical date for Ha Noi and for the whole country in general. For about a thousand years, the capital was called Thang Long, then changing to Dong Do, Dong Kinh, and finally to Ha Noi, in 1831. This sacred piece of land thereafter continued to be the theatre of many fateful events.

As the capital of Vietnam, Hanoi is home to a large number of must-see attractions. Museums and pagodas scatter the city and Hoan Kiem Lake serves as the centre point to reach just anywhere. Hanoi Old Quarter, the cultural, dining, entertainment and shopping heart of the city is worth the majority of your time to discover. If you plan a trip to Hanoi, spare at least a couple of days to explore the city.