noun
main building (of a villa, palace, etc.)
Refers to the principal structure within a larger complex, such as a detached palace, aristocratic villa, or temple compound. Often used in historical or architectural contexts.
平等院の主殿は鳳凰堂と呼ばれている。
The main building of Byōdō-in is called the Phoenix Hall.
この離宮の主殿は江戸時代に建てられた。
The main building of this detached palace was built in the Edo period.