Hidden/exposed observation post on Mintaka III
Hidden/exposed observation post on the Ba'ku planet
A cultural observation post is an outpost camouflaged, usually by a holographic duck blind, and employed by anthropological teams for the purpose of observing species who have not yet discovered the ability to create faster-than-light technologies.
Such societies are designated as pre-warp civilizations and are governed by the Prime Directive. Observation posts allow for covert observation, so as not to disturb the way of the species' life or interfere in the natural evolution of their society.
Observation posts have been employed in numerous situations including missions on Mintaka III, Boraal II and Ba'ku. (TNG: "Who Watches The Watchers", "Homeward"; Star Trek: Insurrection)