In this video students out at survival class have built an all night fire. This fire is meant to be left unattended for many hours, in a survival situation, so that you can perform other tasks without having to keep checking on your fire.

This particular all night fire burned untouched for about 13 hours. While it was not entirely successful, the fire made it through an hour rain storm just after dark and continued to burn throughout the night. I was able to easily get another fire going in the morning using a hot coal from it. It made it 13 hours and only burned approximately 10 logs.