The County of Salem, Massachusetts is located in Essex County. It is the northernmost county in the state and is bordered by the Atlantic Ocean to the east and the Merrimack River to the west. The county seat is Salem, which is also the state's third-largest city. Salem is known for its rich history, including its involvement in the Salem Witch Trials of 1692. The county is home to a variety of attractions, including Salem Willows Park, the Salem Maritime National Historic Site, and the Salem Witch Museum.