I’ll have to disagree with Christ the Redeemer as a Wonder of the World. It’s nice but it’s just a big statue made in modern times.
Unfortunately, I can’t think of a substitute. Structures like the Eiffel Tower have been overshadowed by larger and more grander buildings and towers.
Maybe the Vatican for it’s basic structure and combined artwork.
You’re right - the technical achievement doesn’t seem to be much compared to something like, oh, the Hoover Dam or some other early engineering feat. My amazement is that a Christian religious icon would have been selected.