Bungie has finally nerfed the Treasure Cave in Destiny Patch Notes 22.214.171.124 (9/25/2014) : Hot Fix 5, but it hasn’t stopped players from finding other locations. The treasure cave gave people lots of destiny glimmer and engram drops which not only gave them a shot at obtaining legendary gear but also raising the Cryptarch level.
Post patch, we have another farming location, which isn’t quite as effective but does the job. Let’s see how long this one stays or whether Bungie decides to not do anything about it. The latter will probably not happen.
You can see the new farm location in the video below. This is the best one people have found so far after the patch has come out.