Some aircraft designers believe FS should not only be preserved aircrafts. Therefore you can download cars, busses, ships, and even trains that are simulated just like planes (did you know the stalling speed of a train in landing configuration is 50 knots?) Search for the add-ons at e.g. AVSIM or take a look at the great add-ons on this site.
Now you can transport your passengers between the terminal building and the aircraft or do a sightseeing tour in whatever city you visit.
For example pick a car or bus, start in the southwestern corner of Central Park, New York City, and follow Broadway to the south. You'll see e.g. Flatiron, a building you would never spot from the air.
By the way, what do you call a bus in FS? Answer.