Beacon

Beacons are columns of light in SS undefined and.

Skyward Sword
In SS undefined, when Link places a Beacon on his Map, either on The Surface or The Sky, a blue column of light will appear, acting as a waypoint to reach the desired location. Beacons can only be placed on Overworld Maps by pressing the C Button.

The power to place Beacons is only activated after Link first talks to the aged Impa in the Sealed Temple, at which point only one Beacon can be placed at a time. Once Link reaches the northern portion of the Lanayru Desert where the entrance to the Lanayru Mining Facility is located, Fi will enable the ability to place up to five Beacons on the map.

The Sacred Tears also emit Beacons when Link collects a Light Fruit or when he is being chased by a Guardian in the Silent Realms.

Breath of the Wild
In, Beacons can be placed in with the Sheikah Slate, appearing as green, blue, red, yellow, and purple lights on screen. When the Beacon is placed, it will be shown on the map. Beacaons do not appear in the overworld, and are only visible when viewing them on the Sheikah Slate.