I remember learning th song about Ifca's Castle in grade school in Alden,NY in the late 50's also.

Above a plain of gold & green a young boy's hea is clearly seen.

Chorus

A hoo ya hoo ya hoo ya ya
swiftly flowing Labe
(repeat)

But no tis not his lifting head, tis Ifca's Castle's spires instead.

Chorus

For our pleasure it was made, this grey ol building deep in shade.

Chorus,

I was surprised to hear, from from a Fresh Air child from Queens, NY that we hosted in the early 80's that the song was still being taught in elementary school chorus then,

I don't know about today.