This Monaco-Ville cathedral is probably most popular because it contains the grave of Grace Kelly, the actress-turned-princess of Monaco. Its history also dates a bit further back: The site once held a 13th-century church, but the current cathedral hails from the late 19th century. Inside, you can admire its regal features, which include a white marble altar and an exquisite grand organ. Recent travelers said they were impressed by the beauty of this religious site and highly recommend touring inside.

The cathedral is open daily for tours from 8:30 a.m. to 6 or 7 p.m. – except during Mass services – free of charge. For more information, visit the Monaco tourism board website.