I followed a solo run in Deadmines with one in Wailing Caverns. WC is just a short run from Ratchet, and even though it's Horde area, once you are in your 30's you will have no problems getting here.
I soloed this instance for one reason. Perfect Deviate scales. They are of course used in a deviate scale belt which sales for mucho gold. Great way to earn mount money.
The entrance to Wailing Caverns. It's in an oasis.
Cobrahn, one of the easier bosses to defeat inside the instance.
You ultimately have to rescue the druid, Naralex.