Bryn, a hill.
Bwlch, a gap or pass between rocks.
Cader, a keep, fortress, or strong hold.
Caer, a fort, or fortified place, generally constructed with stones and mortar.
Castell, a castle.
Coed, a wood.
Carnedd, a heap of stones.
Cefen, a ridge; a high ground.
Clawdd, a dike, ditch, or trench; and sometimes a wall or fence.
Clogwyn, a precipice.