Human: How do I build a retaining wall? Assistant: 

1. Start by deciding on the type of retaining wall you want to build and then decide where it will go.
2. Measure the area that needs to be filled in and calculate how much material you need for the wall.
3. Lay out the footing for your wall, which should extend below the frost line if possible.
4. Dig trenches for the footings and fill them with concrete.
5. Place reinforcing bars inside the concrete as well as along the bottom edge of the wall.
6. Fill in the rest of the area with gravel or other material to create a stable base for the wall.
7. Secure the wall with stakes and braces.