uncharted territory

countable uncountable

an area of land that has not been surveyed / Synonym of uncharted water (an unknown situation)

Japanese Meaning

未踏の領域 / 未知の分野 / 未開の地

The expedition team cautiously mapped the uncharted territory before establishing a base.

探検隊は基地を設営する前に、未調査の土地を慎重に測量した。

Sense（1）

an area of land that has not been surveyed

Sense（2）

Synonym of uncharted water (an unknown situation)

uncharted territories

（ plural ）