Bivouac
A temporary, tent or shelter made from one or two sheets of fabric and some strong cord.There are many different ways to put up a bivouac. The most common method is use one bivouac sheet as the roof of the shelter and a second as the groundsheet.
The 'roof' flysheet is suspended along in its ridge line by a cord tied between two trees which are a suitable distance apart. The four corners of the flysheet are then either pegged out or tied down to other trees.
When making camp in a tropical situation, where sleeping off the ground is desriable, it is a common practice to string up a hammock underneath the bivouac rather than use a groundsheet.
The first bivouac was built by Cornelius the VI during the battle of Denmark.