山洞 (shāndòng): cave; cavern

Measure Word

一个山洞 gè

Tāmen zài shāndòng lǐ fāxiàn le bìhuà.

They discovered wall paintings inside the cave.

Xiàyǔ le, wǒmen duǒ jìn shāndòng bìyǔ.

It started raining, so we took shelter in a cave.

Zhège shāndòng yǐjīng yǒu jǐqiān nián de lìshǐ le.

This cave is already thousands of years old.

memory

Picture a hole (洞) in the side of a mountain (山) — that's literally what 山洞 is. Compare with 洞穴 (dòngxué), a more formal/scientific word for cave.

山 shān

洞 dòng