The Hall of the Lost is a giant ruined castle that high-ranking explorers that want more experiance go to. There are an endless numbers of floors and each person who enters takes a different route to their destination.
After a famous explorer dies their whole life is documented then transported to the Hall of the Lost. Explorers who want more experiance will travel to the hall of the lost and take many different routes to get there, based on the route they took they will arive at a chamber where a they relive the explorers life, creating another dungeon for the explorers to venture through. After they finish the dungeon they'll have knowledge of how to be a better explorer and they'll learn a trademark move of the explorer regardless of type.