瑰宝 (guī bǎo): a treasure; a rare and valuable thing

The Mogao Caves in Dunhuang preserve a large number of murals and sculptures and are hailed as a treasure of Chinese civilization.

The jade pendant my grandfather left me isn't worth much money, but it is a treasure of our family.

The museum's most prized possession is a Song Dynasty landscape painting, truly a national-level treasure.

In the eyes of environmentalists, this primeval forest is an irreplaceable treasure in Earth's ecosystem.

"Dream of the Red Chamber" is a treasure of Chinese classical literature, worthy of repeated reading and study.