Upon first opening the expansion area the Ruins seem to serve no purpose other than decorative.
This changes with the Quest: Connoisseurs of Magical Artifacts
At this point they can be clicked.
The Ruins consists of 3 Rune Stones:
Each of the Rune Stones drops quest pieces that power up the Ruins and allows you to harvest each of them for 1xp and 10c every 1h.