The same way you build an 'adult fort', just down size it a little!!
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.
Fort Wayne :)
Fort Necessity
Fort Necessity
Fort Necessity
Fort Mandan
"How to Make Red Fort With Thermocol"
Build a fort!
The Red Fort was build as a capital for the great Mughal Empire
The Red Fort was build as a capital for the great Mughal Empire