BUILD A WALL; CREATE A BARRIER; MAKE A STRUCTURE DESIGNED TO KEEP PEOPLE OUT BY BLOCKING THEIR PATH; TAKE A STRONG MATERIAL SUCH AS STONE AND BUILD IT UP ON TOP OF ITSELF UNTIL IT REACHES A SUITABLE HEIGHT, THEN MAKE IT THE DESIRED LENGTH. THIS IS DONE TO ENSURE THAT WHATEVER ENTITIES YOU ARE SCARED OF CANNOT PASS INTO THE AREA ON THE OTHER SIDE OF THE STRUCTURE.