Trafalgar Square is one of Britain's most famous places, and an important nodal point of London. The junction of [the Strand]?, the Mall, Whitehall and Charing Cross Road has at its centre Nelson's Column, an 185 feet high column supporting a 17 foot high statue of Admiral Nelson, designed by Nash in the 1830s to commemorate Nelson's victory at the Battle of Trafalgar in 1805. On the periphery of the square you find the National Gallery and the church of St. Martin-in-the-Fields. It is also home to the famous/notorious Trafalgar Square pigeons, which Ken Livingstone is trying to eradicate. There are a number of pieces of sculpture in the square in addition to the Column; see Bob Spee's page about them for more information.
As of August 2003, the layout changes to pedestrianise one side of the square - as part of the World Squares For All scheme - have been completed, and the square is a better place for it (IMHO - Earle).
Trafalgar Square is a traditional gathering point for celebrating the new year. It is the location most likely to be seen on television for this. However the crowd is so great that it is not recomended for children, or those with mobility problems. It may be the case that alcohol is banned sometimes at New Year.
Live webcam view from camvista.com: