There are lots of ways to build a fort, but my favorite is:
Open recliners on 2 sofas that look like a half of a square (perpendicular) to each other. Then take 2 chairs and drape blankets from each chair to each sofa recliner, and VOILA! You have a simple fort! Then make any add-ons and have fun!
It took 8 years to build Fort Sumter.
a pillow fort
Google "how to build wooden fort", or something similar. Use the plans to build the fort, but instead of building it on the ground, make the foundation a number of stilts planted several feet into the earth. Build the fort on top of the stilts. Be sure to build a ladder or stairs to get in.
The same way you build an 'adult fort', just down size it a little!!
Fort Wayne :)
Fort Necessity
"How to Make Red Fort With Thermocol"
Fort Mandan
Fort Necessity
Fort Necessity
Build a fort!
The Red Fort was build as a capital for the great Mughal Empire