A helpful resource for all new characters about how and when to unlock content.

And here's a BlueGartr FAQ on all dungeons:


Light Party (4 Players)

Sastasha - Western La Noscea (15-18)
Unlock Condition: Main Story

Tam Tara Deepcroft - Central Shroud (16-19)
Unlock Condition: Main Story

Copperbell Mines - Western Thanalan (17-20)
Unlock Condition: Main Story

Halatali - Eastern Thanalan (20-23)
Unlock Condition: Talk to Nedrick Ironheart in Vesper Bay

The Thousand Maws of Toto-Rak - South Shroud (23-26)
Unlock Condition: Main Story

Haukke Manor - Central Shroud (28-31)
Unlock Condition: Main Story

Brayflox Longstop - Eastern La Noscea (29-32)
Unlock Condition: Main Story

The Sunken Temple of Qarn - Southern Thanalan (32-35)
Unlock Condition: Talk to Nedrick Ironheart in Vesper Bay

Cutter's Cry - Northern Thanalan (35-38)
Unlock Condition: Talk to Silbold in Ul'dah Market Wards

The Stone Vigil - Coerthas Central Lowlands (41-44)
Unlock Condition: Main Story

Dzemael Darkhold - Coerthas Central Highlands (41-44)
Unlock Condition: Grand Company Quest

The Aurum Vale - Coerthas Central Lowlands (47-50)
Unlock Condition: Talk to Nedrick Ironheart in Vesper Bay OR Promotion Quest for GC rank 3

The Wanderer's Palace - Upper La Noscea (50)
Unlock Condition: Clear The Praetorium, then talk to Allene in Vesper Bay

Amdapor Keep - South Shroud (50)
Unlock Condition: Clear The Praetorium, then talk to Nedrick Ironheart in Vesper Bay

Haukke Manor (Hard) - Central Shroud (50 - average ilvl 48+)
Unlock Condition: Clear The Praetorium, then talk to Lauriane in Revenant's Toll.

Copperbell Mines (Hard) - Western Thanalan (50 - average ilvl 48+)
Unlock Condition: Clear The Praetorium, then talk to Hugubert in Revenant's Toll.

Pharos Sirius - Western La Noscea (50 - average ilvl 48+)
Unlock Condition: Clear The Praetorium, then talk to Diamanda in Aleport.

Heavy Party (8 Players)

Cape Westwind - Western Thanalan (49-50)
Unlock Condition: Main Story

Castrum Meridianum - Northern Thanalan (50)
Unlock Condition: Main Story

The Praetorium - Northern Thanalan (50)
Unlock Condition: Main Story

The Bowl of Embers (Hard) - Ifrit (50, average ilvl 49+)
Unlock Condition: Complete The Praetorium, then speak to Thancred.

The Howling Eye (Hard) - Garuda (50, average ilvl 52+)
Unlock Condition: Defeat Ifrit in The Bowl of Embers (Hard)

The Navel (Hard) - Titan (50, average ilvl 57+)
Unlock Condition: Defeat Garuda in The Howling Eye (Hard)

Thornmarch - Good King Moggle Mog XII (50, average ilvl 54+)
Unlock Condition: Main Story

The Minstel's Ballad: Ultima's Bane - Ultima Weapon (50, average ilvl 61+)
Unlock Condition: Complete The Praetorium, then speak to Alys in Revenant's Toll.

The Howling Eye (Extreme) - Garuda (50, average ilvl 65+)
Unlock Condition: Defeat Titan in The Navel (Hard)

Raids (8 or 24 players)

Bahamut's Coil - Eastern La Noscea (50)
Unlock Condition: Defeat Titan in The Navel (Hard)

Labyrinth of the Ancients - Mor Dhona (50, average ilvl 50+)
Unlock Condition: Complete The Praetorium, then speak to the outlandish man at Revenant's Toll.

Reference: http://www.bluegartr.com/faqs/ffxiv/60-how-do-i-unlock-insert-dungeon-here

And pick up those DF entries for Chimera and Hydra so you can help, relic upgrades will mean relic runs.