Prism of Light

In Ultima Online, the dungeon named Prism of Light is located on the northern tip of Nujel'm in Britannia.

Description
The dungeon is unusual, as one does need to pay 10.000 gold pieces admission, before getting a ticket allowing adventuring in the dungeon for 12 hours. While the inside is an adventurer's heaven and even the dungeon itself looks beautiful with all its colorful crystals, it sadly also is the home of the horrible Shimmering Effusion. A very complicated puzzle, which also involves several one-way rooms, has to be solved in order to confront the monster and gain the biggest share of the loot.

However, for final victory, certain criteria have to be met, or death is certain.

Trivia

 * Ressurecting is made a bit easier thanks to a healer camp nearby.
 * Exit is achieved by double-clicking the ticket or, if it has expired, using the help key on your Paper Doll with the option "I am physically stuck in the game," or by defeating the Peerless.