Knowledge ID: 5659

Forest Ronaros Riddle IV

Description
Tulid is a Forest Ronaros, who lives in a deep cave in the Loopy Tree Forest, and has five riddles for you to answer.
Tulid's fourth riddle asks, "When a door closes, the other opens. What is this?"
Details
Knowledge ID5659
Quest Ledger

Errands that explicitly name this knowledge entry in their task ledger.