From Elf Sternberg's The Journal Entries of Kennet R'yal Shardik, et. al., and Related Tales

A large bowl-shaped lagoon cut into the coast-side of the Marbletop Range. A six-klick tunnel is the only easy entrance from the land side. The Marblerun River falls into the Vinyare Sea through a waterfall at the back of the lagoon. The sand at the edge of the lagoon is white, blending into thick tropical vegetation that runs about three-quarters up the sides of the bowl. Castle Shardik Hovers over the lagoon, with access provided by several SDisks placed around and even in it.