You can create a solid box. The base of the box is always drawn parallel to the XY plane of the current UCS (workplane).
You can use the Cube option of the BOX command to create a box with sides of equal length.
If you use the Cube or Length option when you create a box, you can also specify the rotation of the box in the XY plane when clicking to specify the length.
You can also use the Center Point option to create a box using a specified center point.