What Spanish voyagers called "Boca de Ratones" was originally to the south, in present-day Biscayne Bay in Miami-Dade County. The area of Boca Raton was labeled "Rio Seco", meaning "Dry River", during this time. By mistake during the 19th century, mapmakers moved this location to the north and began referring to the city's lake, today known as Lake Boca Raton, as "Boca Ratone Lagoon" and later "Boca Ratone Sounde." An inland stream near the lake was later renamed Spanish River, and eventually became part of the Intracoastal Waterway.