Palace of Nirvana

The Palace of Nirvana arrived in December 2009 with the Rising Tide expansion, together with the Tideborn race and the City of Raging Tides. For years it was the main place to farm materials for Nirvana gear; the same expansion also added a way to upgrade Twilight Temple and Lunar Glade gear, and some Twilight Temple pieces can later become Nirvana gear. Today the wiki describes the palace as an instance used mainly for titles.

• Each run uses one Nirvana Palace Key, sold for Silver Coins by the Mysterious Old Man (665, 128).
• Any Illusion Stone in Archosaur can teleport you there for a fee. On entry you lose all buffs and debuffs.
• If you die, release and talk to the Mysterious Old Man to return to the room you were in. Because of this, many players run it when they have no experience to lose.
• A good squad has a tank, a healer, a debuffer and damage dealers. Every boss uses random aggro and random seals.

• Infernal Lair, Inferno Sovereign: drains mana from range once aggroed, so let a player who needs little mana hold it. Kill the 6 Tombstones to reduce the blue circles, which explode for 5,000 damage each.
• Noxious Den, Noxious Sovereign: an area poison-resistance debuff and a self-buff to its defences. Neither is dangerous, but purging the buff speeds things up.
• Vampire's Domain, Vampiric Sovereign: a deadly area mana drain. Hitting it spawns 6 foxes that must all die at the same moment, and it keeps healing until they do. Kill it within 15 minutes or the whole squad dies.
• Demonic Niche: one of three bosses appears. The Dictator (40%) summons a white add you must not kill and a black add you must kill fast; the Tyrant (40%) makes you run to the far side of the room each time it speaks; the Sovereign (20%) drops two chests and summons weak adds that can stun.
• Ashura's Hollow: again one of three. The Dictator (40%) sends poison snakes you should not kill, since each one explodes when it dies; the Tyrant (40%) drops yellow circles and falling rocks that interrupt casting; the Sovereign (20%) drops two chests and can boost its melee damage, so step back.
• Heaven's Coliseum: the Goldwing Phoenix (40%) grows big at about 40% health and drops flames on players, so damage dealers should attack from range; the Arbiter of Flame (40%) hits for 49% of your health and places flames under players, so spread out; the Ashura Netherqueen (20%) drops two chests, and when she shouts her warning you have about 8 seconds to reach the Mysterious Old Man, whose buff protects you from her huge blast.
• Final boss, Vanished Ancestor: it summons adds whose blast wipes the squad unless they are sealed. Break the one-hit chest monsters to get elemental seals, then use the seal that matches each add's element on it. The Enchanted Ancestor only appears when someone in the squad is on the "99 keys" quest.

Bosses leave Nirvana Palace chests that hold either an Uncanny Crystal or a Mirage Celestone. The better the chest, the higher the share of crystals. Rates from the wiki:

The Vanished Ancestor always drops two items, Uncanny Crystals and/or Rapture Crystals, and the Enchanted Ancestor always drops two Rapture Crystals. Both counts double during drop events. For how these materials fit into gear, see Equipment.