Egmont Key is a 1.7-mile-long island at the mouth of Tampa Bay, just southwest of Fort De Soto Park in Pinellas County. Erosion over the centuries has shrunk the width of the key to about ½-mile. Once a strategic military site, playing major roles in the Seminole Wars, the Civil War, the Spanish-American War, and World War I and II, Egmont Key has been a national wildlife refuge since 1974, providing safety for many endangered or threatened animals such as loggerhead sea turtles and ospreys. It is also a bird nest sanctuary, protecting about 117 species of shorebirds and their offspring.
The Egmont Key lighthouse, which has withstood hurricanes and human battles since 1858 and can be seen from the Sunshine Skyway Bridge, is still a beacon for ships entering Tampa Bay today. At the southern end of the key is a haven for Tampa Bay pilots who are between assignments guiding massive ships through the narrow waterway under the Sunshine Skyway Bridge and into Tampa Bay, but from the late 1800s to around World War II, it was home to the pilots who lived on the key with the lighthouse keepers and the soldiers.
In 1978, Egmont Key was named to the National Register of Historic Places. An assortment of buildings (some merely walls), artillery cannons, and red brick street remnants of the former U.S. Army Fort Dade Military Reservation built in 1898 (then called the United States Military Reservation at Egmont Key and renamed Fort Dade in 1900 after Major Francis Dade who, along with almost all the men under his command, died in a Seminole Indian massacre in 1835) can still be seen today by those who visit Egmont Key, which is accessible only by private boat or by ferry.
You can find this information, and more, in the Thompson book at the Florida History and Genealogy Library:
Thompson, Donald H., and Carol Thompson. Egmont Key: A History. Charleston, SC: The History Press, 2012. Print. R975.965 Thompson.
Interesting links that offer more details about Egmont Key: