"You don't have to be an expert in religious architecture —or even personally religious—to appreciate St. Patrick's, Ireland's largest cathedral and the headquarters of the Church of Ireland. The massive structure is impressively, overwhelming ornate, with intricate tiled floors, vaulted ceilings, grand graystone turrets, and multicolored stained-glass windows. Those visiting for religious reasons can freely walk in and attend a mass or pray independently, but sightseers are asked to donate a small fee. You can also explore the grounds and gardens without stepping foot inside." - Melissa Kravitz Hoeffner