The Trustees of Reservations (TTOR) is a non-profit land conservation and historic preservation organization dedicated to preserving natural and historical places in the Commonwealth of Massachusetts. It is the oldest regional land trust in the world and as of 2016 has 120,000 dues-paying members. In addition to land stewardship, the organization is also active in conservation partnerships, community supported agriculture (CSA), environmental and conservation education, community preservation and development, and green building. The Trustees of Reservations own title to 116 properties on 27,000 acres (11,000 ha) in Massachusetts, all of which are open to the public; it maintains conservation restrictions on 200 more properties. Properties include historic mansions, estates, and gardens; wo