腐海の

of the Sea of Corruption

→ 腐海

phrase Rare #42,266

of the Sea of Corruption Refers to the 腐海, the toxic forest in Nausicaä of the Valley of the Wind. の means “of” and connects 腐海 to the following noun.

JA: 腐海のほとりで静かに暮らしている。

EN: They live quietly by the Sea of Corruption.

腐海の植物ではないか！

Isn't that a plant from the Sea of Corruption!

— 風の谷のナウシカ (1984)

腐海の生まれたわけか

So that's why the Sea of Corruption came into being.

— 風の谷のナウシカ (1984)