Perhaps one of the most attempted photographs taken at Crater Lake National Park is of the curious formation in the lake known as Phantom Ship. This shot, by Rob Mutch, executive director of the Crater Lake Institute, illustrates why.

But what is the Phantom Ship? Here's the National Park Service's explanation:

Among the scenic attractions at Crater Lake, few excel in popular appeal or give rise to greater exercise of creative imagination than the small island known as the Phantom Ship. This rugged little island with its spires of andesite, is generally considered to be no more than a picturesque old rock, furnishing appealing subject for those who would use it as vehicle for their contemplations in fantasy by way of mind, palette, or film. Actually, time is fashioning a biological unit on the island; the usual sequences and consequences of nature are molding discernible, competitive boundaries and patterns of adaptation upon its rugged surface.

Physically, the Phantom Ship is a remaining section of the filled conduit of a fissure from which probably poured many of the lower layers of lava constituting Dutton Cliff. Its rocks of pyroxene andesite have in many places been altered by hydrothermal activity. Quartz filled seems give the rock a character uncommon to most of the rocks generally found on the crater walls. The island is about 500 feet long and reaches a maximum width of 200 feet near the east end. Its east-west ridge of spires, towering 170 feet above the water, sharply divides most of the island into two slopes, one very steeply sloping to the south and the other less steeply to the north. The island is separated from the mainland by a shallow channel about 200 feet wide. Above this channel, Dutton Cliff rises abruptly, constituting one of the highest sections of the south-west wall of the caldera.

For more information on Crater Lake National Park's intriguing geology, check out this page from the Crater Lake Institute.