Ancient structures associated with positional astronomy include:
The unaided human eye can detect about 6000 stars, of which about half are below the horizon at any one time.
On modern star charts, the celestial sphere is divided into 88 constellations. Every star lies within a constellation.
Constellations are useful for navigation. If you live in the northern hemisphere you can find north by locating the star Polaris. This star is always at a position nearly over the north pole.
See also:
wikipedia.org dumped 2003-03-17 with terodump