We round up the best tours of London.

Parliament tour

When the new session of parliament opens each year, it is accompanied by a peculiar rite involving the royal messenger. The messenger must approach the doors of parliament, whereupon they are slammed in the messenger’s face.

The effrontery is supposed to illustrate the independence of parliament, dating back to a time when monarchs were inclined to throw their weight around and politicians were obliged to mark their territory.

This is just one of the anecdotes unearthed during a tour to parliament, or the Palace of Westminster, its full name. Parliament has opened its doors for its summer tours, ensuring the ancient paving stones of Westminster Hall will be brimming with tourists ?until the end of September.

"The Palace of Westminster has been the home to the UK's parliament for  450 years and before that the home of the royal family," tours manager Matt Morgan says. "Its walls house 1000 years of history that have helped shape the nation and parliaments and democracy the world over. 

"The tours follow the route taken by the Queen on the annual opening of parliament from the ornate Lords chamber to the sombre Commons chamber and concluding in the 900-year-old Westminster Hall."

The hall is the oldest building on the Westminster estate, dating back to the 11th century. Its central role in the history of the UK is underlined by the list of men sentenced to death between its walls, William Wallace and Guy Fawkes among them. It is, truly, the seat of centuries-old power.

The rest of parliament was built more recently, after a kitchen fire burned down both houses of parliament in 1834. The Palace of Westminster, as it now stands, was designed to represent the finest Victorian craftsmanship.

The result, visible from the outside but best viewed from beneath the high, airy ceilings and soaring archways, is extraordinary. Each room, each corridor is ornately decorated with mosaics and stained-glass windows.

Augustus Pugin, the man who styled the palace’s interior, is regarded as one of the genius designers of his age. He died young and before his death wrote: “I am 40 years old, but I have worked for 100 years. I am tired.” It is easy to see why.

In the palace's central lobby, where light streams through the tall, panelled windows, the patron saints of the four Home Nations – St Andrew, St George, St David and St Patrick – peer down from stained-glass windows above four separate passages leading to different corners of the palace. As is often noted, St Andrew, the patron saint of Scotland, sits above the path that leads straight to the bar.

In the next room across, in the members' lobby, bronzed statues of four British PMs – Winston Churchill, Lloyd George, Margaret Thatcher and Clem Atlee – tower in the corners of the room.

Churchill's statue is based on a photo during the Second World War, when parliament had been reduced to rubble during the blitz.

Alongside is the Churchill Arch, a piece of stonemasonry damaged in the Blitz, which Winnie insisted be salvaged and incorporated into the repaired parliament.

20 Dean's Yard, City of London, SW1A 0AA?
parliament.uk
Tube: Westminster
£15

Sex and the city: Keep it clean

Nothing to do with the cult TV show ?– instead, this tour explores London's smutty history. You'll wander through the history of vice in the capital, taking in the sex trade, various tabloid scandals and the most sordid dark corners of the city. So much for the Brits being prim and proper – they've been debasing themselves for centuries.

Saturdays & Wednesdays
St Paul's Churchyard, EC4M 8AD
walkcity.co.uk
Tube: St Paul's

£8

South Bank photography tours, Happy Snapping

It's a cut above your garden-variety sightseeing tour, with a special emphasis on taking high-quality photographs. It's part guided tour, part photography workshop,
and it all comes together on the banks of the Thames, with panoramic views of Westminster and the steepling London Eye in the background.

A great way to create some unique memories of London.

Various dates, mostly weekends
In and around Westminster
londonphototours.co.uk
Tube: Westminster

£85

On the waterfront, Down by the river

Learn the history of the Thames and how it shaped London. Equally, chart the way the riverfront has been revamped by recent developments and urban renewal programmes.

Saturdays & Wednesdays
St Paul's Churchyard, EC4M 8AD
walkcity.co.uk
Tube: St Paul's

£8

Blood and bones: heroes and villains

London wasn't always a glamorous, shiny city. Indeed, back in the day, it was full of thugs and ne'er-do-wells.

Saturdays
St Paul's Churchyard, EC4M 8AD
walkcity.co.uk

Tube: St. Paul's
£8

Olympics walk: a prelude to 2012

This time next year, London's Olympic sites will be overflowing with human traffic. The new facilities promise to have a transformative effect on east London, ?so get in early and see how they're taking shape.

11am daily
In and around London's Olympic sites
toursof2012sites.com
Tube: Bromley-by-Bow

£9

Street art london

East London is famous for its slightly grittier, more urban aesthetic, and this tour will leave you feeling like you're getting your hands dirty. Tread the backstreets of Shoreditch and Brick Lane, taking in the street art that has come to epitomise the east's reputation for breaking the mold.

Tuesdays, Thursdays, Saturdays
Foundry Building, Old St
streetartlondon.co.uk
Tube: Old Street
£10

Hitchcock walk

Hitchcock is indelibly linked to Hollywood, having created the template for the modern thriller, but he had a successful career in his country of birth before shipping out for America ?in 1939. This tour, run by one of the UK's foremost Hitchcock experts, traces the director's steps in London as well as some of the famous scenes from his films.

Mondays, Wednesdays, Saturdays
Bayswater or Queensway
sandrashevey.tripod.com
Tube: Bayswater
£25

Open spaces

You'll be amazed at the secluded green spaces hidden away in the middle of London. There's a treasure trove of rooftop gardens and secret churchyard grassy patches.

Sundays 11.30am
Outside St Paul's Tube
londonhistorywalks.com
Tube: St Paul's
£8

Electric ?bike tours

You choose your own tour depending on which sights you want to see and then hop on to your electric bike which whizzes along the streets at 15mph.

Daily 10am & 4pm
Through central London
londonelectricbiketour.com
Depends on the tour
£35

Alternative London

A tour of east London that promises to show off the parts of the capital you won't find in guidebooks.

Wending its way through Brick Lane and Shoreditch, the tour takes in plenty of street art, but also stops off at the most interesting bars and vintage shops in the area. A great way to scratch the surface of one of the capital's most storied corners, with the benefit ?of local knowledge.

Tuesdays-Thursdays & Saturdays
Old Spitalfields Market, E1 6DT
alternativeldn.co.uk
Tube: Liverpool Street
Free

City cruises on the Thames

The Thames affords sightseers views of London they simply won't get while walking its streets. Jump aboard a river liner and snake along the Thames, underneath London's famous bridges, taking in the skyline of the capital on either side, whether it's the jagged skyscrapers of the City or the no less recognisable lumpiness of the Tate and Battersea power station.

Daily
Westminster Pier, SW1A 2JH
citycruises.com
Westminster Pier

£8

London architecture

Pick an area of London that interests you and a time that suits, before being guided through the capital's ever-changing skyline.

londonarchitecturewalks.com
£15

Jack the Ripper tours

The Whitechapel murders of 1888 were the first great tabloid crime story, and the killings continue to captivate, partly because the culprit was never caught.Daily 7.30pm

Various Ripper sites in the east
walks.com
Tube: Tower Hill
£8

Harry potter: Definitely no Quidditch

Unfortunately, you won't actually go through Diagon Alley or board the Hogwart's Express, but you will wander through the London sites that featured in the eight blockbuster films. A well-rounded tour of London for the Potter-obsessed.

Wednesdays, Saturdays, Sundays
Meeting points depend on which tour
walks.com
Tube: Temple, Westminster or Bank

Celebrities ?of mayfair

Explore the pop-culture legacy of this plush London address, passing celebrity homes and hang-outs as well as famous film locations.

Saturdays 11am
Henry's Café Bar, 80 Piccadilly
thecelebrityplanet.com
Tube: Green Park
£8

Is london haunted?

After visiting ?a series of spooky sights and downing a few pints, you may well come to believe that it is. A journey into olden days superstition.

Wednesdays 7.30pm
Around central London
walks.com
Tube: Holborn
£8

Intelligence trail

Discover the behind-the-scenes intrigue of Britain's intelligence services during this tour ?of MI5 and MI6 facilities. ?For years, the world of espionage has been bubbling away beneath the surface of the capital, with rogue spies, double agents and KGB operatives making up a fascinating cast of characters. Beginning in Westminster, the tour takes you through the very heart ?of British power.

Sundays 2pm
The Mall, near Admiralty Arch
intelligencetrail.co.uk
Tube: Charing Cross

£15

Beatles london

The Beatles may have been formed in Liverpool but they cast their shadow all around London as well. This tour takes ?you through the studios where they recorded some of their most famous tracks as well as the parts of London the members of the band called home at various times. You'll also visit some of their favourite hang-outs and the famous zebra crossing at Abbey Road.

Friday-Sunday
Underneath Marble Arch
thecelebrityplanet.com
Tube: Marble Arch
£15