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