Let me tell you a little bit more about the geography of where I am living before we start talking about chalk!I am living in a city called Brighton, which is located on the southeast coast of England. England is one of four countries (England, Scotland, Wales and Northern Ireland) that make up the United Kingdom, or U.K.All four of the countries that make up the U.K. are part of a big chain of islands located off of the northwest coast of Europe. Most of the southeastern part of England, and many other parts of the U.K., are surrounded by water. The city that I live in, Brighton, is near the coast. I get to live very close to the beach. So, what does all this have to do with the cool cliffs that I saw this week? It's actually quite important to understand the history and geography of England in order to understand how these cliffs were formed.The beautiful white cliffs that I have told you about, run all along the coastline here in England. You will not see them unless you are near the sea. This is because about 25 million years ago, when the island was created, the whole southern part of England was covered in a chalk dome. Chalk is a type of white rock that forms deep under the sea. It is formed from the minerals that are left behind from the bodies of dead sea creatures. Over millions of years, the chalk dome slowly eroded. Now all that is left are the edges, which run up and down the English coastline. These left-over edges are the beautiful white cliffs that we see today.