Dakota Fire Hole

A Dakota Fire Hole is basically an ancient form of Rocket Stove, that was used by Native Americans.  Not only is it an efficient way to cook food, in areas with scarce fuel.  It uses the same basic principles of insulation, draft, and a concentrated, reflective fire chamber, while hiding your firelight, and minimizing any smoke that might attract unwanted attention from potential enemies.

Here is a really good link on how to build one including the dimensions:  http://survivaltopics.com/the-dakota-fire-hole/