Some interesting and rather beautiful photos of airports from above.

[Major Nikon]

5. Occassionally in a small plane you can get clearance to fly directly over the top of big airports

Since the takeoff and landing traffic doesn't traverse directly over the top of the airport, you can go right over the top without interfering with the traffic and it saves you time compared to going all the way around. I've done this at DFW many times and a few times at some of the other really big airports. The view is quite impressive, especially at night, because for a few moments you get a ringside seat to one of the best shows in town. At DFW they routinely land 3 or 4 airplanes simultaneously while two more are taking off.