1. Florence, Italy: This city is a gallery of world-class art and architecture. A curator’s dream, the top sights include Michelangelo's David, Botticelli's Birth of Venus and Brunelleschi's Duomo. The town itself is a masterpiece: Its bridges, buildings, streets, towers and sidewalks were painstakingly constructed by stonecutters. With its warm trattorias, upscale shops and small luxury hotels, the city is a Tuscan treasure.2. Buenos Aires, Argentina: The country’s capital exudes an air of the exotic, smoky and mysterious that is embodied by its tango salons and sophisticated café life. Now recovering from a period of economic crisis, the city has been called the Paris of South America for its neoclassical buildings on tree-lined boulevards. The Museo del Arte Latinoamericano de Buenos Aires (MALBA), created by young Argentinean architects in 2001, is a symbol of the city’s modernity.3. Bangkok, Thailand: The yin-yang relationship between the old and the new is ever present in Thailand's capital city. Its 10 million residents strive to preserve the past (the Grand Palace) and expand for the future (with high-end shopping and luxury hotel developments that are among the best in Asia). The authenticity of the city’s centuries-old culture can be discovered in its narrow alleyways, away from the grinding traffic, where visitors can find silk and handicrafts by local artisans.4. Rome, Italy: Once you see the Colosseum, venture to the Via Veneto, visit the Vatican and marinate in the history, art and architecture of the capital, indulge in Rome's la dolce vita. After the sunset casts its colorful glow on the Eternal City, romance fills the night air (take an after-dinner stroll with a loved one ...