lol there are no eterna ruins that was just in the anime.
Pokemon Diamond, Pearl and Platinum has Eterna Forest.
In the north of Eterna Forest.
In the Eterna gym in eterna city.
Eterna forest
In Eterna Forest
In eterna forest.
it's between Eterna Forest and Eterna City
In Eterna Forest.
Eterna forest
in eterna city
a dog in eterna forest
in eterna forest