Kastanas Beach in Milos is a hidden gem on the island's east coast, boasting vibrant red, orange, and yellow rocks that contrast beautifully with the crystal-clear turquoise waters. This secluded beach is perfect for snorkeling, with a diverse marine life to discover. While the pebbly shore may require water shoes, the lack of facilities and difficult access make it a peaceful spot to unwind and enjoy the natural beauty of Milos.