Sappers. They've been used through most of military history as a means to neutralize fortifications, either by digging out underneath walls to make them collapse, or digging a space for a bomb under a trench in the first world war (subsequently detonated, destroying both the trench and most to all of the soldiers within)
Battlements? You may need to be more specific, there are kind of a lot of things on castle walls...
a mushroom
Smooth Muscle
cardiac muscle
sucrose
posters
vegetal cell
Multicellular organisms whose cells have nuclei but don't have cell walls are called anamalia cells
The answer is a mushroom. It has the word room in it. But no walls.
Mainly conduction.
Plant cellsBacterial cellsFungi
Plants, fungi, bacteria, and some protists have cell walls. The composition and structure of cell walls can vary between different types of organisms.