Neath means "beneath". (Preposition. UK.)
Meaning: sob, debaixo, embaixo (de)
You should read this article: https://www.englishexperts.com.br/forum/below-beneath-under-down-t1058.html
stars and sun we wandered = Sob o sol e as estrelas nós viajamos
the waves = Sob as ondas.
Source: COLLE, Tom. The Preposition Book
. Michigan Publisher. 2006.