Tech Duinn
"Tech Duinn, an islet far from Dal Riata, is the gathering place for fallen heroes, awaiting their rebirth. Once a paradise, now it has been cursed and corrupted by Crom's fallen servants. The curse is that of a fog that renders any heroes lost within it, unable to ever be reborn. If you wish to avoid the fate of the lost, go forth and lift the curse, before it is too late." - Visage of Donn.
Leystone areas
Bull Rock, this would be the first ley and would be near the entrance of Tech Duinn. Bull Rock would feature a couple dolmen arranged around it.
https://en.wikipedia.org/wiki/Dolmen
Altar of Crom, this would be the second leystone. This leystone would feature an alter and two quest bosses nearby.
House of Donn, this would be the third and last leystone. This would have a small town with a tomb in the center of the town. Donn would be standing outside the tomb, and you would finish the questline here. Behind the town would be the raid boss.
Bosses
High King, Tigernmas, level 220 6* raid
200+ legacy bosses could be moved here. ( Just a suggestion since i feel they don't really fit in at carrowmore.)
Priest of Crom, level 220 5* there will be two of these positioned near the Altar of Crom leystone. You would need to kill these with a group as part of the questline.
Mobs
The fallen, levels 200-220 1-2*
Crom's cultist, levels 200-220 3*
Corrupted Hero, levels 200-220 4*
To gain access to Tech Duinn, you would have to be a minimum level of 200 and would have to complete a quest that would prove to Donn that you're strong enough to lift the curse.
Name: Katau
World: Herne