How to prompt: Build an Impregnable Fort

For today's prompt you don't have to title your piece "How to ..." (though you certainly can if you'd like to) or even make it a step by step process like a recipe, the process should merely be described at some length during your piece.

How to Build an Impregnable Fort

One thing to remember is that "fort" is both a thing for kids to play in as well as a military base in which people fight and actually die. Also the idea of an "impregnable fort" can be quite metaphoric: how to make a stand for or against something less tangible than a snowball or cannonball.