Coming face to face with one of the world's most recognisable landmarks is always a surreal moment, but in the case of the Houses of Parliament it's a revelation. Photos just don't do justice to the ornate stonework and golden filigree of Charles Barry and Augustus Pugin's neo-Gothic masterpiece (1840).

Officially called the Palace of Westminster, the oldest part is Westminster Hall (1097), which is one of only a few sections that survived a catastrophic fire in 1834. Its roof, added between 1394 and 1401, is the earliest known example of a hammerbeam roof and has been described as the greatest surviving achievement of medieval English carpentry.

The palace's most famous feature is its clock tower, aka Big Ben. Ben is actually the 13-ton bell, named after Benjamin Hall, who was commissioner of works when the tower was completed in 1858.

At the business end, parliament is split into two houses. The green-hued House of Commons is the lower house, where the 650 elected Members of Parliament sit. Traditionally the home of hereditary bluebloods, the scarlet-decorated House of Lords now has peers appointed through various means. Both houses debate and vote on legislation, which is then presented to the Queen for her Royal Assent (in practice, this is a formality; the last time Royal Assent was denied was 1708). At the annual State Opening of Parliament (usually in November), the Queen takes her throne in the House of Lords, having arrived in the gold-trimmed Irish State Coach from Buckingham Palace. It's well worth lining the route for a gawk at the crown jewels sparkling in the sun.

When parliament is in session, visitors are admitted to the House of Commons Visitors' Gallery . Expect to queue for at least an hour and possibly longer during Question Time (at the beginning of each day). The House of Lords Visitors' Gallery can also be visited.

Parliamentary recesses (ie MP holidays) last for three months over summer and a couple of weeks over Easter and Christmas. When parliament is in recess there are guided tours of both chambers and other historic areas. UK residents can approach their MPs to arrange a free tour and to climb the clock tower.