#2. Rio is named for a river that doesn’t exist
Rio de Janeiro was first discovered on January 1, 1502. The Portuguese explorers, led by Gaspar de Lemos, came across Guanabara Bay and named it Rio de Janeiro, or January River. The city was official founded on March 1, 1565, and was called São Sebastião do Rio de Janeiro (Saint Sebastian’s January River) to pay tribute to King Sebastian’s patron saint.