Triangle

The Triangle is a secret level in Tony Hawk's Underground 2, unlocked only by completing Classic Mode on any difficulty. The map itself is a remote island in the Carribean, strewn with shipwrecks, downed aircraft and bizarre ruins, with an alien base carved into the interior of the island itself.

Origin
The entire level is a nod to the conspiracy theories surrounding the Bermuda Triangle.

Level Specific

 * A stranded pirate ship with a pedestrian pirate walking around on its deck. It is obviously taken from THPS3 level Skater Island.
 * A hidden alien base, which can be accessed by grinding on the missles of a wrecked Apache helicopter, blowing off a chunk of the mountainside.
 * A small, severed section of a passenger airplane on the shoreline. Inside, a skeleton is still strapped into one of the seats.
 * Commercial airplanes flying in and out of portals in the sky in the background.
 * An offshore UFO firing a death ray at something in the water.

Tony Hawk's Underground 2

 * High Score - 500,000 / 1,000,000 Points
 * Pro Score - 1,000,000 / 2,000,000 Points
 * Sick Score - 1,500,000 / 3,000,000 Points
 * High Combo - 400,000 / 750,000 Points
 * Collect S-K-A-T-E
 * Collect C-O-M-B-O
 * Collect 5 Treasure Chests
 * Find the Secret Tape
 * Activate the Triangles
 * Bust a Lip Trick on the UFO!

Trivia

 * The Triangle is an obvious nod to the real-life Bermuda Triangle, an area of the Atlantic Ocean connecting Tampa, San Juan and Bermuda, infamous for a large number of ships and aircraft purportedly disappearing within under mysterious circumstances, usually blamed on paranormal and/or extraterrestrial activity. The most famous victims of the Triangle include Flight 19, The Marine Sulpher Queen and the USS Cyclops.