Hey you! Yes, you! Thank you for adding beauty to the world!
Definitions of castellation:
noun: (uncountable) The act or process of making a building into a castle.
noun: (uncountable) The addition of battlements to a building, as for example when a feudal manor house needed fortification against border-raider attacks.
noun: (countable) Any of a set of slots or grooves in an object, often machined into a metal part, as for example on a castellated nut.