While it is technically possible to do a day trip from London to Cornwall, it is highly discouraged because of the sheer distance. The journey by train from London Paddington to Penzance takes roughly 5 to 6 hours each way, meaning you would spend 10 to 12 hours on a train just to spend 2 or 3 hours in Cornwall. Driving is equally grueling, often taking 5 hours without traffic—and traffic to the West Country is notorious. If you are determined to see it in a day, your only realistic option is to fly from London Gatwick or Stansted to Newquay Airport, which takes about an hour. However, once you land, you’ll still need a car to see the sights. Most travel experts suggest a minimum of three days to truly enjoy the rugged coastline, Tintagel Castle, and the famous Cornish pasties without feeling exhausted.