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.
Birka
Both Rimbert and Adam were German clergymen writing in Latin. There are no known Norse sources mentioning the name of the settlement, or even the settlement itself, and the original Norse name of Birka is unknown. "Birca" is the Latinised form given in the sources and "Birka" its contemporary, unhistorical Swedish form. The Latin name is probably derived from an Old Norse word "birk" which probably meant a market place. Related to this was the "Bjärköa law" (bjärköarätt) which regulated the life on market places in Denmark, Norway and Sweden. Both terms in different forms are very common in Scandinavian place names still today leading to speculation that all references to Birca especially by Adam of Bremen were not about the same location.