The lagoon and lakes were part of a half-mile (0.8 km) wide swamp, west of which was scrub land a mile (1.6 km) wide (part of the Atlantic coastal ridge) where the Florida East Coast Railway (1896) and Dixie Highway (1923) were built. To the west of the scrub was a half mile or wider swamp within which flowed north to south the "Prong of Hillsborough River", which is now the El Rio Canal. It now forms the eastern border of Florida Atlantic University and the Old Floresta neighborhood. The prong entered the "Hillsborough River" at the present eastern end of the straight portion of the Hillsboro Canal (dredged 1911–14), which is the southern city limits. The river flowed southeast in several channels along the western edge of the present Deerfield Island County Park, formerly called Capone Island (named for Al Capone who owned it during the 1930s), which did not become an island until the Royal Palm Canal was dredged along its northern edge in 1961. Flowing south from the lagoon to the river along the eastern edge of the 'island' was a "Small boat Pass into Hillsboro' River", also called the Little Hillsboro. The river continued due south about just inland of the coastal dune until it emptied into the Atlantic Ocean at the "Hillsborough Bar", now the Hillsboro Inlet.