I'm currently staying in London for a week and would love to escape the city for a day to see some of the surrounding countryside or historic towns. I'm planning to rely entirely on the rail network, so I'm looking for destinations that are easily accessible within a 90-minute train ride. Does anyone have recommendations for charming spots that are perfect for a solo traveler or a couple? Any tips on which stations to depart from or how to save money on tickets would also be greatly appreciated.