Stellwagen Bank National Marine Sanctuary (SBNMS) is located at the mouth of Massachusetts Bay. The sand and gravel plateau that gives the sanctuary its name was formed by the slow retreat of massive Ice Age glaciers, which sculpted the dynamic seafloor. The nutrient-rich waters above and around the bank support a diverse ecosystem that has been a famous fishing ground for more than 400 years and claims status as the birthplace of East Coast whale watching. Historic New England shipping routes cross the sanctuary, and over the course of centuries, the seafloor has become a repository for shipwrecks – time capsules of our maritime heritage. The entire sanctuary encompasses 842 square miles of open ocean 25 miles east of Boston. Visitors to SBNMS can enjoy whale watching, bird watching, diving and fishing in this history-rich and biologically-diverse habitat.