From Heathrow Terminals 1-2-3 Underground Station Tube to London Kings Cross then train to Kings Lynn. 3hrs 07min £38. From Heathrow Central Bus Station line 727 bus to Thetford, Bus Interchange then line 40 bus to King's Lynn, Transport Interchange. 5hrs 50min. From London Heathrow Airport (LHR) drive to King's Lynn. 2hrs 10min £24.