Once a month, the barriers separating Norrath from other worlds become thin and portals appear in the form of enchanted mushroom rings. These portals transport the user into an enchanted grotto whose inhabitants may be willing to reward you with interesting items in return for a little bit of assistance. This event should be automatically active from 12:01 am on the 20th to 11:59pm on the 21st of every month (PST), gremlins permitting.