Simplify the following text for a Grade 11 native English-speaking person.
Original: At Titan 's south pole , an enigmatic dark feature named Ontario Lacus was the first suspected lake identified , possibly created by clouds that are observed to cluster in the area .
Simplified: At Titan 's south pole , an large dark area named Ontario Lacus was the first lake identified , possibly created by rain as clouds are often seen in the area .