From Longman Dictionary of Contemporary Englishthe depths of the ocean/countryside/forest etcthe depths of the ocean/countryside/forest etcDNMIDDLEthe part that is furthest away from people, and most difficult to reach Astronomers may one day travel to the depths of space. → depth
Examples from the Corpus
the depths of the ocean/countryside/forest etc• The sporadic gunfire, explosions and shouting in the depths of the forest, seemed to belong to a different world.• So the depths of the oceans are full of lights moving rhythmically around and continually turning off and on.• Illegal activity is not limited to the depths of the forest. 