Plum Island (New York) in the context of "Block Island Sound"

Plum Island Animal Disease Center (PIADC) is a United States federal research facility dedicated to the study of foreign animal diseases of livestock. It is a national laboratory of the Department of Homeland Security (DHS) Directorate for Science and Technology (S&T), and operates as a partnership with the U.S. Department of Agriculture (USDA). The facility's director is Larry Barrett.

Isolated on Plum Island off the eastern tip of Long Island, New York, the center has been tasked with protecting America's livestock from animal diseases since 1954. It is the only facility in the country authorized to work with live foot-and-mouth disease (FMD) samples, and specializes in the study of FMD and African swine fever. At the height of the Cold War, study of biological weapons for use against livestock was conducted at the site, ending in 1969 when President Nixon declared an end to the United States' offensive bioweapons program. Today the facility maintains laboratories up to biosafety level 3, and has remained controversial as a result of its high-risk work and proximity to the New York metropolitan area.

Fort Terry was a coastal fortification on Plum Island, a small island just off Orient Point, New York, United States. This strategic position afforded it a commanding view over the Atlantic entrance to the commercially vital Long Island Sound. It was established in 1897 and used intermittently through the end of World War II. In 1952, it became a military animal and biological warfare (BW) research facility, moving to civilian control in 1954 as the Plum Island Animal Disease Center. Despite the new civilian control, the biological warfare mission continued until 1969, when the US officially ended offensive BW research. The island is now being considered for sale or conversion to a wildlife refuge. Fort Terry was listed on the National Register of Historic Places in 2021.

Plum Island Light is located on the western end of Plum Island, which lies in the Long Island Sound, east of Orient Point at the end of the North Fork of Long Island, New York. A historic granite lighthouse originally built in 1869 sits at the site, but no longer serves as an active aid to navigation. It was listed on the National Register of Historic Places in 2011.

A short distance northwest is a 14 feet (4.3 m) metal tower that holds the automated light that has served as an aid to navigation since the earlier light was decommissioned in 1978.