Nothing, especially if the airport is in a relatively uninhabited area. More important, you don't see a horizon. Use whatever visual references are available, but also use the attitude indicator to set climb attitude and keep the wings level. On especially black nights, monitor the vertical speed indicator to avoid accidentally stopping the ascent and leveling off, or even descending. The eyes We're diurnal rather than nocturnal animals, and therein lies the problem.
Human eyes perform poorly at night and are easily fooled by illusion as well.
Light-sensitive nerves in the back of the eye are divided into rods and cones. Both can adapt to night vision, but rods, used for peripheral vision during day or night, are much more sensitive. Unfortunately, rods are not in the center of the eye. Consequently, pilots should look slightly off to one side of an object to see it best. The center portion of the back of the eye is occupied by cones.