One of the most iconic images of England is that of the Houses of Parliament (House of Lords and House of Commons), and its famous clock tower (Big Ben). Situated in the heart of London, for centuries the site of British government and law, it's an impressive collection of beautifully constructed buildings. Here they are, photographed at dusk, nicely lite up and reflected in the River Thames.
Tours are available of this historic complex and if you're lucky (or unlucky, depending on your point of view) you might be able to see politicians debate each other. Some tours are restricted to British citizens, but others are open to tourists from any country. Visiting the Houses of Commons is an interesting half day diversion when in Westminster; perhaps couple it with a visit of the nearby Westminster Abbey and you've a most memorable and unique travel day.