memorial hall; museum (commemorating a person or event)
Typically a building or facility dedicated to preserving the memory of a notable person, historical event, or achievement. Often used in proper names like 〇〇記念館.
来週、漱石記念館に行く予定です。
I plan to go to the Soseki Memorial Museum next week.
この記念館は、戦争の記憶を伝えるために建てられました。
This memorial hall was built to pass on the memory of the war.
Compound of 記念 (commemoration, memory) and 館 (hall, building). The reading is standard on'yomi.