Saugus Iron Works is a reconstruction of the first successful, integrated iron works in the New World. It produced wrought iron and cast iron products from 1646 to approximately 1670, utilizing the most advanced iron-making technology in early Colonial times. On April 5th, 1968 the site was renamed Saugus Iron Works National Historic Site and became part of the National Park System because of its significance to the character, development, and history of the United States.

The Saugus River and Turning Basin are fundamental features of the historic landscape. The tidally influenced river is a natural resource for the wide variety of plants, animals, and other organisms that depend on the river, riparian woodlands, and surrounding marshes as an important habitat.