Guildford is on the main railway line between London Waterloo and Portsmouth. Half-hourly train services run from Guildford to Waterloo, with journey times of around 40 minutes. For further information, go to the National Rail website. You can walk from the station to Stag Hill campus within around 10/15 minutes, catch a taxi from the front of the station, or take a number 1 or 17 bus from the back of the station.
RailAir coaches connect Guildford railway station with Heathrow Airport Terminal 5 and Heathrow Central Bus Station every hour from early until late, seven days a week. Gatwick station is positioned in the South Terminal of the airport and provides direct rail-air link trains to Guildford hourly between approximately 5:15am (6am on Sundays) and 11pm. Check the National Rail website. Travel from the other London airports (Luton, Stansted and City) is much more complicated and time consuming.