Modeling and editing solids and surfaces. Primary solids. Boolean operations, Autocad.
Use guidelines to draw a spline. Revolve the spline. Change the UCS to mirror the revolved spline on different planes. From the new shape substract a cube. Create a star-like volume. Substract a sphere.
Create level curves. Move them at different height. Use loft command to create terrain.Thicken the surface and with the help of a box create a terrain block.