Eureka, California
"Eureka" received its name from a Greek word meaning "I have found it!" This exuberant statement of successful (or hopeful) gold rush miners is also the official motto of the State of California. Eureka is the only U.S. location to use the same seal as the state for its seal.
Europa (consort of Zeus)
It is common in ancient Greek mythology and geography to identify lands or rivers with female figures. Thus, "Europa" is first used in a geographic context in the Homeric Hymn to Delian Apollo, in reference to the western shore of the Aegean Sea.
As a name for a part of the known world, it is first used in the 6th century BC by Anaximander and Hecataeus.
The weakness of an etymology with εὐρύς ("eurus"), is 1. that the -u stem of εὐρύς disappears in Εὐρώπη Europa and 2. the expected form εὐρυώπη euryopa that retains the -u stem in fact exists.