The First Era land of Cyrod, although fairly extensive, does not cover the entirety of modern Cyrodiil. There are a number of Ayleid cities marked on the map that cannot be entered, and some that are not marked that also cannot be visited. There are some standard monsters and animals in the wilderness, as well as Ayleid Soldiers patrolling in pairs on the roads.
Ayleid Wells, which are no longer ruined, and at least some of the various Magical Stones can also be found in the same places that they are in modern Cyrodiil. There are naturally no Imperial cities or ruins, although there are several dungeons and caverns.
This is where you appear in First Era Cyrod at the end of the quest Raid on Castle Relleis. Nearby are Ovidius, who will start the quest Liberate Vindasel, and the damaged Crusader's Relics, which will start the quest Recovering the Crusader's Relics.
A single zone cavern that appears to be unchanged.
Visited during the quest Liberate Vindasel, this is an Ayleid city that is currently under attack by Alessian forces. Outside the entrance are a dead Alessian Soldier and a dead Ayleid Soldier.
(4) Felgageldt Cave
A two zone dungeon consisting of Felgageldt Cave and Felgageldt Wishbone Vault, this looks to be identical except that the Bandits are no longer present and instead there are five Ayleid Soldiers and two Aurorans in Felgageldt Cave and by two Ayleid Soldiers in Felgageldt Wishbone Vault.
(5) Greenmead Cave
A three zone dungeon which consists of Greenmead Cave, Greenmead Soggy Hollows and Greenmead Inky Grottos, this appears to be identical to the standard cavern.
A former Ayleid city now occupied by Alessian forces, this is visited during the quests The Slave Queen, Reforging the Crusader's Relics, The Spirit Barrier, The Song of Pelinal and The Covenant.
(7) Haynote Cave
The three zones of this catacomb are Haynote Cave, Haynote Basin Galleries and Haynote Winding Sump, which all appear to be identical to the Third Era place.
(8) Yellow Tick Cave
The two zone dungeon consisting of Yellow Tick Cave and Yellow Tick Hollows is the same except the Conjurers in the first zone are no longer there and instead there are eight Ayleid Sorcerers and those in the second by seven Ayleid Sorcerers.
Sercen is an Alessian occupied former Ayleid city that is entered during the quest Reforging the Crusader's Relics.
(10) Wellspring Cave
Wellspring Cave is visited during the quest The Arrow of Time. The Necromancers are no longer present and instead there are Ayleid Soldiers, although the latter may be missing, making the area completely deserted.
(11) Memorial Cave
As it is in the present day, Memorial Cave is a Vampire lair.
(12) Upper Vanua
Upper Vanua is a two zone abandoned Ayleid city that is visited during the quest The Covenant.
(13) Lower Vanua
A single zone abandoned Ayleid city with an underwater entrance in Lake Rumare that is visited during the quest Little Brother.
(14) Shinbone Cave
A two zone catacomb which consists of Shinbone Cave and Shinbone Galleries, this appears to be an unchanged Goblin lair.
(15) Mingo Cave
This is a single zone cavern that appears to be identical to the one in the present.
(16) Charcoal Cave
This is a three zone dungeon that consists of Charcoal Cave, Charcoal Cave - Abandoned Tunnels and Charcoal Cave - Inner Lair. This largely seems to be identical to the normal one except that in Charcoal Cave the two Bandits have been replaced with Ayleid Soldiers and in Charcoal Cave - Inner Lair - the Bandits have been replaced by 5 Ayleid Soldiers and 2 Aurorans.
(17) (Waterfall Cave) Shrine of the Eight
The shrine is visited in the quest Shrine of the Eight.
(18) Pothole Caverns
A single zone complex whose Necromancer inhabitants have been replaced by an Auroran and eleven Ayleid Soldiers, but which otherwise appears to be unchanged.
(19) Horn Cave
Consisting of three zones, Horn Cave, Horn Cave Still Pools and Horn Cave Grottoes, the only difference here would seem to be that the Bandits in Horn Cave have been replaced by an Auroran and four Ayleid Soldiers.
(20) Nenyond Twyll
This is a two zone Ayleid city visited in the quest The Spirit Barrier. Prior to this the door will not open.
This is a three zone lair consisting of Fatback Cave, Fatback Great Chamber and Fatback Deep Basins. Apart from a couple of dead Ayleids this appears to be identical to the Third Era goblin lair.
Dzonot is a two zone dungeon consisting of Dzonot Cave and Dzonot Main Cavern. In Dzonot Cave the Bandits have been replaced by 2 Aurorans and a 3 Ayleid Soldiers; in Dzonot Main Cavern they have been replaced by an Auroran and an Ayleid Soldier. The areas otherwise appear identical.
(23) The Tower of White Gold
The Tower is surrounded by a barrier that prevents access, until it is visited in the quest The Song of Pelinal. There are Ayleid Soldiers and Aurorans surrounding and inside the Tower, but by the time they are reached, they are mostly all dead with the exception of some in the central chamber. The Tower of White Gold Basement can be reached using the Glass of Time in the Lord's Quarters of the Castle of the Nine in the present.
(24) Sinkhole Cave
This is a two zone complex consisting of Sinkhole Cave and Sinkhole Great Hall. The Bandits in Sinkhole Cave have been removed and are now four Ayleid Soldiers and two Aurorans, but the remainder appears to be the same apart from the fact that one of the doors between the two areas is missing, resulting in a bottomless drop in the second zone.
(25) Meteorite Fissure
This underwater fissure at the bottom of Lake Rumare is entered during the quest Reforging the Crusader's Relics. Outside the entrance are 2 Titanite Crystals.
(26) Wellspring Island
The island is reached from Wellspring Cave and is visited during the quest The Arrow of Time. On the island are five Ayleid Soldiers and two Aurorans.
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