From Elf Sternberg's "The Journal Entries of Kennet R'yal Shardik, et. al., and Related Tales"
Decanting Difficulties, 112/0741
Marbletop gets its name because that's exactly what it is. Imagine, if you can, a mountain range rising up from sea level, and then slicing it cleanly off at around 30* meters, disposing of all that rock, and polishing the exposed surface until it was nearly reflecting, and you'll have Marbletop. At it's narrowest Marbletop ridge is six kilometers wide, at it's widest it's about thirty. It runs nearly 25,000 kilometers along the Vinyare Coastline.
The only two geographic formations
visible on top of the Marbletop Range are the Marblerun River
and the Marbletop Chess Board
* elsewhere it is referred to as 20 meters tall, but from a subjective perspective.