"Where a Rock meets the Sky" is a riddle in Dunkelzahn's Will giving the hint of a location with 2 million nuyen, some (magical?) amulets, and a stockpile of weapons. In order for someone to obtain the rewards located there, they have to complete a series of tasks and have an Animae confirm they completed the tasks.
However the most logical theory is Red Rocks Amphitheatre in the PPC sector of Denver. The term rock isn't literal, but is figurative for Rock n Roll. The tasks would probably had something to do with preparing for the arrival of Ghostwalker, such as undermining the Aztlan district of Denver, and making behind the scenes deals with the other NAN nations and the UCAS and CAS. And if the tasks weren't completed in the allotted time then Ghostwalker himself would have been able to use the nuyen to start to build his domain.