a marvel to behold

A person or thing that is particularly spectacular, wondrous, or exhilarating to witness. They're trapeze act is a marvel to behold—I can't believe that they do their routine without a safety net! It's easy to forget that the technology we take for granted today would be a marvel to behold just a few years ago.

marvel to behold

someone or something quite exciting or wonderful to see. Our new high-definition television is a marvel to behold. Mary's lovely new baby is a marvel to behold.