YOU SAID:

There is a cave up on the mountain.

INTO JAPANESE

山の上に洞窟があります。

BACK INTO ENGLISH

There is a cave on the mountain.

INTO JAPANESE

山に洞窟があります。

BACK INTO ENGLISH

There is a cave in the mountain.

INTO JAPANESE

山には洞窟があります。

BACK INTO ENGLISH

There is a cave in the mountain.