Complex sentence: The first known European to view the lake was Francisco Álvares, who passed near it 21 September 1520; he mentions the lake had hippopotamuses and catfish, and the land around it were planted in lemons, oranges and citrons.
Split into simpler sentences: The first known European to view the lake was Francisco Álvares, who passed near it 21 September 1520. He mentions the lake had hippopotamuses and catfish, and the land around it were planted in lemons, oranges and citrons.