Kassiopi Castle is a ruined Byzantine fortress on a rocky peninsula above the harbor of Kassiopi in northeastern Corfu. Its position once controlled the sea passage between Corfu and the mainland coast. Surviving walls, towers and gates follow the irregular terrain, while vegetation now covers much of the enclosure.
The ascent and interior of Kassiopi Castle include uneven stone, exposed drops and limited shade, so visitors need secure footwear, water and care around ruined edges. Historic walls should not be climbed or used as seats, and loose masonry must not be disturbed. The monument is best visited in suitable daylight and weather. Any temporary closure, conservation barrier or fire-risk restriction should be followed even when an older guide describes unrestricted access.