From Durham, we took a bus north to Newcastle. Compared with Durham Village, Newcastle is a big city. At Durham Railway Station, I also saw several students going to Newcastle for dinner. The train arrived in about ten minutes. Here I actually saw the city wall, Hadrian's Wall. In fact, this is the northernmost border of the British province of the Roman Empire. It is similar to the city wall in China, both of which are used to defend against invasions from the north. Along the Tyne River from west to east is the entrance to the sea. In those days, the King of England built some castles here, consisting of a wooden spire main building and an earthen outer wall. New Castle is the source of the name Newcastle.