Rocks.
Steps:
01. Following the geometry already laid out, or while laying out a geometry, place rocks around the perimeter of the finished figure
NOTE: Distinct rocks can be placed to align with celestial features, landmarks, or other intents
CAUTION: rocks can be heavy and lifting heavy objects can be dangerous
This manifestation method is used in the following examples and tracings:
Beaghmore, Stonehenge, Callanish