mausoleum
noun
"Mausoleum" is a big building or structure where the graves of deceased or important people are placed.
Example
- The Taj Mahal is a beautiful mausoleum in India.
 - The Lincoln Memorial is a mausoleum in Washington, D.C., that honors President Abraham Lincoln.
 - The Tomb of the Unknown Soldier is a mausoleum in Arlington National Cemetery that honors American soldiers who died in wars.