Uncharted and Untrodden

Uncharted adjective - (of unknown regions) not yet surveyed or investigated.

Untrodden and uncharted are semantically related. In some cases you can use "Untrodden" instead an adjective "Uncharted".

Untrodden adjective - Not having been traveled over or through.

Uncharted and untrodden are semantically related. Sometimes you can replace term "Uncharted" with "Untrodden", this adjectives are similar.