Complex sentence: Euesperides was probably founded by people from Cyrene or Barca on the edge of a lagoon which opened from the sea, and at the time may have been deep enough to receive small sailing vessels.
Split into simpler sentences: Euesperides was probably founded by people from Cyrene or Barca on the edge of a lagoon which opened from the sea. At the time, the lagoon may have been deep enough to receive small sailing vessels.