These: http://www.bneymeir.com/AllSites/500/Assets/runway_lighting.jpg
I drive past two sets of them on the way home from work every night, and they fascinate me. When I’m perpendicular to them, the lights on each tower seem to flash almost (almost) simultaneously, but when they pilot approaching the runway sees them, they flash in sequence.
Anyway, do they have an official name besides “runway lights on towers”?