National Museum, Dublin

Housed in a graceful building that is itself a sort of exhibit (with classically Victorian architecture and a rotunda based on Rome’s Pantheon), this archaeological museum explores Ireland’s ancient Celtic heritage. One of the highlights inside is the Ór collection—priceless prehistoric golden artifacts, including torcs (twined metal rings worn as jewelry) that date back to 2200 B.C. Another is the Medieval Collection, which contains iconic pieces like the Ardagh and Derrynaflan chalices—two perfect examples of the delicacy and beauty of eighth-century ecclesiastical metalwork.