Built on the site of St. Brigid’s monastery, which was founded in the 5th century, this beautiful 13th-century church dominates central Kildare. Its exquisite stained-glass windows portray Ireland’s three great saints: Patrick, Colmcille, and Brigid. The round tower on the grounds is the second tallest in the country (33m/108 ft.); it dates to the 10th century, although its original pointed roof was later replaced by a Norman turret. If the groundskeeper is in, you can climb the stairs to the top for €7. Near the tower, a strange-looking stone with a hole at its top is known as the “wishing stone”—according to lore, if you put your arm through the hole and touch your shoulder when you make a wish, then your wish will come true. The Cathedral is closed to visitors from October to April, but you can usually visit the grounds year-round, free, by asking at the Heritage Centre on Market Square.