Answer: cupolaed

AnswerCrossword Clue
CUPOLAEDLike many state capitols
cupolaeda rounded vault resting on a usually circular base and forming a roof or a ceiling
cupolaedraised observation post in the roof of a railroad caboose
cupolaedsmall structure built on top of a roof
cupolaedvertical cylindrical furnace for melting iron in the foundry that has tuyeres and tapping spouts near the bottom