Points of Interest (POIs) are commonly objects and encounters found on the surface of landableplanets and moons. Depending on the site type a Points of Interest may be persistent. Note that the Category "Point of Interest" in the Navigation Menu also shows System Signal Sources.
Flying a Ship at around 2 km above the surface. Blue circles on the scanner display mark areas which contain a Point of Interest. These fade out below 2km, vanishing fully at about 1.5km. Unless you spot the point of interest visually, it is best to land and switch to an SRV to use the Wave Scanner to finish tracking it down. Persistent POIs can be discovered by using the Detailed Surface Scanner to map a planet. These are primarily Geological or Biological POIs. Following the scan they are shown when approaching the planet and also in the System Navigation Panel.
Threats
Some points of interest are guarded by NPC soldiers, mercenaries and Skimmers, which have Bounties. The Skimmers are initially buried, and will unearth themselves when the POI is approached. Be on guard for potential reinforcements while scavenging.
If there is a trespass zone marked in red on the scanner display, lingering in it for too long will trigger the hostility of the skimmers. If the POI is in an area ruled by law and the skimmers do not have bounties, lingering in the trespass zone can also give fines and bounties. Shooting the skimmers earns you a bounty on your head.