London was first mentioned in 61 A.D. It was called Londinium then. The first settlements were built on two hills on the North bank of the River Thames to avoid the danger of flooding. Today these two areas are Westminster and St.Paul's. They are linked by the Strand.
The Romans made Londinium a large city and built walls around it. We learn where some gates of the city walls stood from such names as Bishopsgate, Ludgate, etc.
One of the most interesting ways to see London is to go down the Thames from Westminster Bridge to the Tower of London or even to Greenwich. From the River Thames much of the city's history can be seen through its buildings.
For over 1000 years the Thames was the busiest road of London, the narrow streets being inconvenient for traffic. Hundreds of boats sailed the river. All and everything was transported by water, even the prisoners were taken to the Tower by boat.
The Tower of London is its most interesting link with history, dating back to the 11th century. It was built by William the Conqueror to impress the Saxons and to guard the river approaches to London. It was once a citadel, a royal palace, a state prison, a mint, now it is a museum.
In 1666 a great fire hit the city destroying most of the buildings. To commemorate the Fire a tall column 202 ft high was erected not far from St.Paul's cathedral. Both of these were built by the famous architect Sir Christopher Wren.
After the Fire houses were built of stone and brick instead of wood and plaster, the streets were made much wider, London healed its wounds and became one of the biggest cities of the world.