A great deal of Borg drones in an otherwise open terrain
Open country or open terrain was a type of terrain typically located in a countryside that was mostly flat and free of trees and other obstructions.
In 2024, at the Château Picard, Seven of Nine and Raffaela Musiker had to run through open terrain that was crawling with Borg drones in order to reach the La Sirena. (PIC: "Hide and Seek")
On a planet somewhere in the Delta Quadrant, a hologram of Leonardo da Vinci (using a mobile emitter) and Captain Kathryn Janeway crossed open country in 2374 to find a storage facility where stolen technology from their ship was being stored. (VOY: "Concerning Flight")