Whitehall runs from Trafalgar Square in the north to Westminster Square in the south.
Halfway down Whitehall you can catch a glimpse of 10 Downing Street and The Cenotaph, a Memorial for both the World Wars.
Other buildings on the street include...
The Ministry of Defence.
The Horse Guards building (former headquarters of the British Army), which is a large building in the Palladian style between Whitehall and Horse Guards Parade. Horse Guards is always guarded by troopers of the Household Cavalry, both mounted and on foot. Two mounted cavalry troopers are posted outside daily from 10 am to 4 pm, and are relieved every hour.
The Admiralty (former headquarters of the Royal Navy).
Also on the road is an equestrian statue of George, Duke of Cambridge, a former Army Commander-in-Chief.
10 Downing Street
10 Downing Street, which is about halfway down Whitehall, is the historic office and home of the British Prime Minister and No 11 the official residence of the Chancellor of the Exchequer. However, at the moment Tony Blair, the current Prime Minister, lives at No 11 as this is a larger property for his family. Number 10 is also the venue for the regular Cabinet meeting. The Cabinet meets every Thursday while Parliament is in session in the Cabinet Room, which has used by successive Cabinets since 1856.
A police officer traditionally stands outside the black front door of Number 10 — a door which can only be opened from the inside.
10 Downing Street is not open to the public. Up until the 1980s you could walk down Downing Street, but when Margaret Thatcher was Prime Minister gates were installed at either end to protect against a possible IRA terrorist attack.
The Cenotaph (a tomb or a monument erected in honor of a person or group of persons whose remains are elsewhere) is very close to 10 Downing Street, in the centre of the road of Whitehall . On the Sunday nearest to 11th November at 11am each year, a Remembrance Service is held at the Cenotaph to commemorate British and Commonwealth servicemen and women who died in the two World Wars and later conflicts.
It was designed and built by Edwin Lutyens between 1919-1920 at the request of the then Prime Minister Lloyd George to replace an identical plaster cenotaph erected in 1919 for the Allied Victory Parade. The inscription reads simply "The Glorious Dead".
Official 10 Downing Street Web Site