This is what I remember singing at school, in the 70's. In New Zealand.!!

Upon the plains of gold and green,
A young boys head,
is clearly seen,
A hoya hoya hoy ya ya
Swiftly flowing river,
A hoya hoya hoy ya ya
Swiftly flowing river

But no 'tis not,
a young boys head,
It is gods Castle spire instead,
A hoya ....