Destiny's new expansion House of Wolves has a secret area that nobody knew about until today, when Trials of Osiris became available.
Watch Our First Runs Through Destiny's New Trials Of Osiris Mode
A region called The Lighthouse is now available to only the best players in the new Crucible mode, unlocking only for those who finished their Trials Passage with a perfect 9-0 record. You can see the area and its short introduction cinematic in the video below from Destiny player and YouTuber MrJonathannovak1.
At The Lighthouse there's a rewards chest for the impressive performance, similar to the large chest found in the Prison of Elders. It gives the player an Exotic, a Legendary, and other items--perhaps the same guaranteed drops as the Prison of Elders chest. Other than those rewards there doesn't seem to be anything in the area, with a few empty (but interesting) rooms and halls.
Destiny's House Of Wolves Expansion Is Now Live, Details Here
The Trials of Osiris, accessible to those who own the new House of Wolves expansion, encourages you to enter with a well-oiled Fireteam--simply playing the mode with anyone won't be a recipe for success. The rewards are handed out for how well you do: when you buy entry into the mode, you can play until you win nine matches or lose three games.
The rewards at Brother Vance in the Vestian Outpost are accessible depending on the number of wins you manage to compile. Win just two and you can buy the Stone Tier reward package. The rewards go up to the Gold Tier package, available if you manage to win all nine matches, with other packages and some gear awarded at three, five, six, and seven wins. Those who finish without a single loss are, apparently, also allowed access to The Lighthouse, and can buy the Gold Tier because they won nine matches.