Rockingham County is a county located in the U.S. state of New Hampshire. The county seat is Brentwood. Rockingham County is included in the Boston-Cambridge-Newton, MA-NH Metropolitan Statistical Area. The Rockingham County Botanical Garden was a botanical garden located in Brentwood. Strawbery Banke Museum in Portsmouth is a collection of historic buildings from the seventeenth through nineteenth centuries. Canobie Lake Park, located in Salem, is an amusement park that opened in 1902. Also in Salem is Rockingham Park racetrack, which features weekly horse racing and is next to the Mall at Rockingham Park. Rockingham County is also home to New Hampshire’s entire seacoast and features several popular resort towns. Hampton Beach has a boardwalk and Hampton Beach Casino Ballroom. The town of Rye features several undeveloped beaches such as Odiorne Point State Park and contains New Hampshire’s portion of the Isles of Shoals.