I need a sunny spot to bask and reproduce.
Box turtles need sunny clearings, wet or dry. Without, individuals and the colony will languish. Turtles bask for warmth throughout the growing season, and at any hour of the day. Late in fall, especially, they seek direct sunlight. Successful nesting requires a site with full sun exposure.
A useful clearing is 100 feet or more wide, north to south. (East-west dimensions are less critical.) Sunlight must reach brush piles at the north edge at least until frost. If your land makes that impossible, put brush piles to the east, for afternoon warming in autumn. On small lots, open a triangular clearing, pointing south or southwest.
Keep shrubs and grass sparse. Turtles like to see both sky and earth. Both sexes use clear areas for basking, travel corridors, and mating. In open sand, or a sandy blowout, keep plants from colonizing every nook. Dry sand is an ideal nesting medium, especially on a flat plain or slight south facing slope.
In a sunny spot, you can encourage nesting. Here and there, cut ground vegetation harshly. Tear out some weedy grass clumps or seedlings to break the surface. If soil is compacted, dig up a few pockets of sand the size of a small soup kettle. Remove sticks and root balls from the turned soil. Some of these nesting pockets are for turtle use. Others will keep predators occupied, sifting sand in all the wrong spots.
Isolate these nesting pods. A mown path to connect the dots offers a buffet table for raccoons. Control your curiosity, too. After you travel the path on foot, predators will follow your scent at twilight, just as female turtles begin to lay eggs.
Box turtles share urges with seagoing turtles. Gravid females often return to the spot where they hatched, if they can. By preserving open sand, you provide a beach in their otherwise leafy ocean. The fewer features in the sand, the better. Turtles can find the right place to lay eggs. Footpaths and landmarks help only the raccoons and other nest predators.
For more box turtle stewardship guidelines, see Habitat from Humanity.