“ The Chinese, when attacking a castle or fort, flew kites over the city wall and used the length of string it took to get it there as a measurement to know how far they had to dig a tunnel to get under the wall.”
“ Certain trees have sap that is filled with magical potential. Their sap is harvested and distilled down to produce various types of potions, much like maple syrup is collected in some areas. The magical effects of these syrupy potions are often fairly trivial; perhaps they simply cause the imbiber to grow hair more quickly, summon butterflies, or walk a few inches above the floor. People enjoy the syrup as a flavoring, instead of imbibing it for its magical powers.”
“ A cave with weapons sunken into the walls, blades sticking out of the floor and ceiling, and so on. Possibly, any weapon used in it could be torn out of the hand and sink into the stone.”