Do a search on here for cinder block pits, there have been a few posted. Growing up, it's what we cooked on, but it was fed with coals from a fire barrel. My dad and uncles didn't have temp probes and such, it was all done by feel and looks. This was 30-40 years ago.
Now I control temps by limiting the inlet air with the exhaust wide open. That's what I do on my offsets and grills...