london is a great and old city . Have you been to london ?

Yup, I have been there three times. It is a very large cosmopolitan city. But the structure of the transportation is very clear for a newcomer to travel around London. There are many famous landmarks in London including the Tower Bridge, Big Ben (as you mentioned), Buckingham Palace, St. Paul's Cathedral, British Museum and many more. In a bit further from central London, you can visit Greenwich, the home for the standardization of clock.

I lived in London for more than twenty years and I love the place. It is a huge, noisy city but there are quiet areas and beautiful parks too. There is no fog now but the air is polluted by traffic fumes. Drivers now have to pay an extra charge to drive in central London, and this makes it much more pleasant to walk around, because there is less traffic and the air is cleaner. I love the great museums and I have been in many of the historic buildings, including the Houses of Parliament. I often walked along the banks of the River Thames, which flows through London, and where the best views are to be seen. I have many good memories of life in London. Most of all I remember some of the people I met there. I got to know people from many different parts of the world, who had moved to London to live and to work.