Fort Perch Rock is a coastal defence battery built between 1825 and 1829, with the foundation stone being laid in 1826. It was built to protect the Port of Liverpool and proposed as a fortified lighthouse to replace the old Perch Rock Light; however, a separate lighthouse was built. The fort was built on an area known as Black Rock, and was cut off at high tide. However, coastal reclamation has made it fully accessible. It is currently open as a museum.