For centuries, Portugal's aristocracy considered Sintra — just 15 miles northwest of Lisbon — the perfect place to escape from city life. Now tourists do, too. Sintra is a mix of natural and man-made beauty: fantasy castles set amid exotic tropical plants, lush green valleys, and craggy hilltops with hazy views of the Atlantic and Lisbon. It was the summer escape of Portugal's kings, and those with money and a desire to be close to royalty built their palaces amid luxuriant gardens in the same neighborhood. Lord Byron called this bundle of royal fancies and aristocratic dreams a "glorious Eden," and even though it's mobbed with tourists today, it's still magnificent. With extra time, explore the rugged and picturesque westernmost tip of Portugal at nearby Cabo da Roca.