Britain's Best Buildings

Tower Bridge, in London, conceived and built during the 1870s, 80s and 90s, encapsulates the struggle between the artist architect and the engineer, between a concern for history (the new bridge had to sit happily beside the ancient Tower of London) and the application of modern building technology. Tower Bridge is - in a very idiosyncratic way - a happy marriage of these potentially conflicting concerns, and perfectly encapsulates the topsy-turvy artistic tastes and values of late Victorian Britain.

Blenheim Palace, in Oxfordshire, whose construction was started in 1705, is an extraordinary monument to both national and personal glory, and the story of its design and development reveals much about the national and international political struggles of the early 18th century. It also tells of the different tastes in classical architecture that divided artistic opinion in the years between 1700 and 1730. It is a palace built, almost literally, on blood. The palace - and the estate in which it stands - was the gift of a grateful monarch and nation to a general - the Duke of Marlborough - for an epoch-making victory in 1704 over the French armies of Louis XIV. So it can hardly be said to be a typical English country house, especially since its massive and theatrical Baroque architecture - the work of Sir John Vanbrugh and Nicholas Hawksmoor - is packed with military references and unsubtle triumphal symbolism. The process through which Blenheim Palace was created is not only a story of high drama - of collapsing finances and political in-fighting and betrayal - but also throws light on the way in which a great work of art, a complex and corporate enterprise, is achieved.

Durham Cathedral was the most daring structure of its age - the first structure of the modern age. With its astonishing grasp of engineering - thrust and counter-thrust - it was a century ahead of any other building in Britain. Dan Cruickshank also reveals a building that is as puzzling as the pyramids but which, with the right key, he is determined will give up its ancient secrets. "Nothing is constructed by chance - every piece of the puzzle has a meaning - even the things that look like mistakes. Each has a secret message to impart", says Cruickshank. Meanwhile monks' skulls reveal a luxury lifestyle, while records of tightrope walking and sexual incontinence cast an altogether different light on monastic life. And what is the explanation behind the cathedral's modern invention?