Hard to believe that one of the world's most famous palaces started life as a simple townhouse - built not for a monarch but for the Duke of Buckingham in 1703. Queen Victoria was the first royal to actually live here, moving in during 1837, though she promptly complained it was too small. With 775 rooms she may have had a point. Keep an eye on the flagpole - when the Royal Standard flies, the King is home. And despite the armed guards, the gilded gates and the thousands of tourists, the palace has a surprisingly patchy security record - your guide will reveal some of the more extraordinary break-in stories that have left the royal household rather red-faced over the years. From its unlikely origins to the balcony moments that have defined the modern monarchy, there is far more to this building than meets the eye.

Buckingham Palace is the destination, but The Mall is the red carpet. This dead-straight ceremonial avenue was originally a croquet lawn - the game "pall mall" gave it its name, before it was reinvented as London's grandest processional route. The flags lining both sides represent every Commonwealth nation, so on a breezy day it feels like the whole world is welcoming you to the palace. This is where London stages its greatest spectacles: Trooping the Colour, royal wedding processions, and the victory parades that marked the end of two world wars. As you pass, your guide will point out Clarence House and St James's Palace - between them these two buildings have housed monarchs, princes and the odd royal scandal for the better part of five centuries.

The oldest of London's royal parks, and arguably the most beautiful. The view from the bridge across the lake, with Buckingham Palace in one direction and the domes and spires of Whitehall in the other, is like a fairytale. Once a Royal Zoo, it is now home to over 15 species of bird including the famous pelicans, overly friendly squirrels and a host of other wild surprises!

Think the guards outside Buckingham Palace are impressive? Wait until you're standing inches from a mounted soldier of the Household Cavalry - the same regiment that has protected the monarch since Charles II returned from exile in 1660. This was once Henry VIII's personal jousting ground, where Tudor knights charged at each other for the king's entertainment. Today the entertainment is rather more civilised, though no less theatrical. Your guide will also let you in on a secret: that unassuming little doorway in the corner? It's technically the back entrance to Buckingham Palace.

It looks like an ordinary Georgian terraced street - and that is entirely the point. Number 10 Downing Street is the most famous address in British politics, yet from the outside it could almost pass for any London townhouse, were it not for the armed police, the famous black door and the gaggle of tourists pressed against the security gates. Your guide will reveal that the door is actually fake - the real entrance is around the back - and that the building is far larger than it appears, connecting through to a vast complex of offices and state rooms behind the modest facade. This is where decisions are made that shape the world, in a building that looks like it should have net curtains and a recycling bin outside!

The clock tower that has become shorthand for London itself - though almost nobody calls it by its correct name. Big Ben is actually the nickname of the great bell inside Elizabeth Tower, named after Sir Benjamin Hall, the rather large Commissioner of Works who oversaw its installation in 1859. The bell has cracked twice, been silenced for repairs, and once stopped the entire country in its tracks when it chimed thirteen times on a BBC radio broadcast - a moment so alarming that listeners called in convinced the nation was under attack.

One of the oldest seats of democratic power in the world, where the decisions (and occasionally the scandals) that shaped an empire were debated, plotted and sometimes shouted across the chamber. Your guide will bring the stones to life with the stories of the figures who walked these corridors: kings who lost their heads, politicians who changed history, and at least one infamous plot to blow the whole thing up.

Every coronation since 1066. Seventeen royal weddings. The funerals of kings, queens, poets and warriors. If the walls of Westminster Abbey could talk, they would barely know where to begin. This is the church where William the Conqueror was crowned on Christmas Day, where Elizabeth I and Mary Queen of Scots - mortal enemies in life - lie buried just feet apart, and where more recently a young prince married a girl from Berkshire in front of a global audience of two billion people. Look up at the Gothic towers and you are looking at nearly a thousand years of British history compressed into a single building. Your guide will reveal the stories behind the famous tombs, the Coronation Chair, and the rather extraordinary collection of monarchs, warriors and writers who have made this their final resting place.

London's great public living room - the place the city comes to celebrate, protest, mourn and occasionally just feed the pigeons. The square was built to commemorate the Battle of Trafalgar in 1805, where Admiral Lord Nelson defeated the combined French and Spanish fleets at the cost of his own life. He now stands 52 metres above the square on top of his column, guarded by four enormous bronze lions cast from the cannons of defeated French warships. But your guide will also point out the details most visitors walk straight past: the fourth plinth in the corner, which has hosted some of the world's most provocative contemporary art installations since 1999, the smallest police station in the United Kingdom hidden inside a lamppost in the corner, and the bronze plaques on the ground that mark the official centre point from which all distances in Britain are measured.

When the Luftwaffe reduced much of the City of London to rubble during the Blitz, one image above all others came to define British defiance - the great dome of St Paul's Cathedral rising through the smoke, unbowed and unbroken. The photograph became one of the most iconic of the Second World War. But the cathedral's story begins long before Churchill's finest hour. This is the fourth St Paul's to stand on this site - its three predecessors were variously destroyed by fire, Vikings and the Great Fire of London in 1666. The current building is the masterpiece of Sir Christopher Wren, who is buried inside beneath a simple stone slab bearing the inscription: if you seek his monument, look around you. Your guide will reveal the secrets of the Whispering Gallery, where a word murmured against the wall can be heard clearly on the opposite side 34 metres away, the tombs of Nelson and Wellington, and the story of the royal wedding that captivated the world in 1981.

London has had a market on this spot for over a thousand years - traders have been selling food in the shadow of London Bridge since at least 1014, making Borough Market one of the oldest in the entire country. Today it is one of the greatest food markets in the world, a gloriously chaotic cathedral of cheese, charcuterie, fresh bread, street food and produce from every corner of the globe. The Victorian wrought iron structure that houses it sits directly beneath the railway arches, so trains rumble overhead while you browse. Your guide will navigate you through the stalls, pointing out the traders who have been here for generations alongside the newcomers who are redefining British food culture. Whether you are after an award-winning cheese, a freshly baked sourdough or simply the best cup of coffee in London, Borough Market delivers.

In September 1666, a fire that started in a baker's shop on Pudding Lane burned for four days and destroyed 13,200 houses, 87 churches and the medieval heart of the city. The Monument built to commemorate it is a masterpiece of hidden mathematics - if you were to topple it, it would fall exactly to the spot where the fire began. At 62 metres it remains the tallest isolated stone column in the world, and climbing its 311 steps rewards you with one of the great views across the City of London. But your guide will also reveal the darker side of the story - a French watchmaker named Robert Hubert confessed to starting the fire deliberately and was hanged for it, despite the fact that he hadn't even arrived in London until two days after it began. The inscription blaming Catholics for the fire remained carved into the stone for 150 years.

Nearly a thousand years of imprisonment, execution and intrigue within a single fortress on the Thames. William the Conqueror began building the Tower in 1078 not just as a castle but as a statement of power - a reminder to the people of London of exactly who was in charge. It has since served as a royal palace, a prison, an armoury, a zoo and the home of the Crown Jewels. The list of famous prisoners reads like a who's who of British history - Anne Boleyn, Thomas More, Lady Jane Grey, Guy Fawkes - most of whom left via the scaffold rather than the front gate. Your guide will point out the Traitors' Gate through which prisoners arrived by river, the towers where the young princes mysteriously disappeared in 1483, and explain why the ravens that stalk the grounds are officially employees of the Crown, with their own pension and a Yeoman Warder assigned to their care.

It is the most photographed bridge in the world, yet most people call it by the wrong name - this is Tower Bridge, not London Bridge, a mistake that has confused tourists for over a century and once led an American businessman to accidentally purchase the wrong one. Built between 1886 and 1894, the Victorian Gothic towers were deliberately designed to blend with the Tower of London next door, disguising what was at the time the most sophisticated bascule bridge ever engineered. The two massive drawbridges can still be raised in just a few minutes to allow tall ships through, a sight worth stopping for if you are lucky enough to witness it. Your guide will also tell the story of the RAF pilot who in 1952 found himself unable to stop his bus in time as the bridge began to rise - and made the split-second decision to accelerate and jump the gap!