There's nothing better than traveling by train, especially when the train is comfortable, quiet, is punctual and goes through beautiful landscapes. The trip from London to Edinburgh is amazing, it takes just 4 hours, and the amazing landscape doesn't let you detach yourself from large windows. The train starts at Kings Cross station and ends at Waverley, Edinburgh's main station. The route is through the very green English countryside, past large rivers that run for many kilometers and the sea. The only thing I recommend is that you buy food and drink before boarding asprices on the train are exorbitant.