A small portion of Charlestown is north of the Mystic River, containing the northern approach to the Malden Bridge and now the entrance to Encore Boston Harbor (which made jurisdiction over the casino a matter of dispute). This land was formerly a peninsula, but landfill has more completely connected it to the mainland of Everett. This boundary was part of the original 1649 separation of Malden from Charlestown, where the Penny Ferry operated at the time; the first bridge opened on the site in 1787.