A few players were asking about the Secret Room Tickets earlier today, since the low-level bosses are getting attention again due to Constellation Symbols. The bosses of the 4 old dungeons can drop colored tickets which allow access to secret rooms where you can loot some random elite equipment from treasure chests. See also Colored Tickets of the Secret Rooms (sGE) and 2ch Wiki (jGE).
|Red||Dilos Latemn||Al Quelt Moreza Parsonage (G8)||Lv.28 Elite|
|Yellow||Treasure Golem||Tetra Ruins Catacombs (I8)||Lv.36-52 Elite|
|Blue||Chimera||Porto Bello Cabin (B7)||Lv.52-68 Elite|
|Green||Ravyn's Heart||Skeleton Dungeon 1F (K5)||Lv.84 Elite|
Furthermore, there is a hengestone inside the Red Ticket Secret Room. [Source] For other hengestones, see Wiki of the New World.