International Rose Test Garden, Portland, Ore.
Make time to stop and smell the roses—all 10,000 of them—at Portland's International Rose Test Garden. This 4 1/2-acre garden features new varieties of roses, beautifully maintained landscaping, and the Shakespeare Garden, which includes herbs, trees, and flowers mentioned in The Bard's works. The rose garden has been in use since 1917, and it even harbored hybrids from Europe for safekeeping during World War I. The best time to visit is June through October, when the roses are in bloom, but the grounds are open year-round. It's free to look in the garden, but don't touch—you'll face a $500 fine if you try to take any roses home with you.