Building an underground fort is a terrific learning experience and a great chance to be creative. It takes some time and effort to create a fort that can last a while.
1. Find a clearing in a field or in a wooded area. Make sure there are no utilities, cables, exposed rocks or roots running through the area where digging is planned.
2. Mark off the length and width dimensions of the underground fort with stakes. Begin digging the desired depth (3 to 6 feet). Move the dirt away from the edges of the hole as it’s being removed, to keep it from falling back into the opening.
3. Dig around tree roots or cut them back level with the walls. Pull out large rocks and use the resulting space as a shelf for a lantern or candle. Make sure the earth is stable after removing rocks or root ends.
4. Line the floor of the fort with a tarp or water-resistant drop cloth. Leave about 6 inches of space around the edge of the floor covering and dig a small trench for water to run off in the event of rain.
5. Shore up the sides of the fort with long planks of wood. Salvage scrap wood from building sites or dumpsters. Set the planks flush against the walls of the fort and drive the ends into the floor.
6. Cover the opening with a large sheet of plywood. Camflogue the wood with sticks, grass and dirt, or build a roof for the fort. Use long tree limbs and boards and make the roof about a foot wider all around than the opening.
7. Fill in openings with leafy branches, pine cones and clay. Lay the roof over the opening. Secure it with a large rock placed at each corner.
8. Choose a location off the beaten path to keep passers-by from walking over the fort. Blend in the roof area with the surroundings. Leave sufficient room for an exit.