18 days in United States & Central Portugal Itinerary

More than the country of car-packed streets seen in TV shows and movies, the United States of America is a complex and diverse home to over 300 million people living in a wide range of landscapes and climates. From its big-city skyscrapers to its sprawling natural parks, the country's ''melting pot'' combines many ethnic groups that share a strong sense of national identity despite their cultural differences. A country of road trips and big blue skies, the United States harbors orderly cities filled with restaurants, parks, museums, and innumerable sightseeing opportunities, as well as pristine natural areas perfect for a holiday in the great outdoors. To see as much as you can of this diverse land quickly, drive over some of the more than 6 million km (4 million mi) of highways leading through deserts, mountain peaks, fertile fields, and giant urban centers.

Central Portugal contains some of the most prosperous and densely populated areas in Portugal, as well as thick pine and chestnut forests spread across a series of rugged mountain ranges. Inhabited since well before the Roman occupation of the Iberian Peninsula, this part of the country remains best known for its capital Coimbra, which features a historic Old Town retaining much of its medieval look and feel. Beyond the busy regional capital lies Portugal's tranquil countryside, frequently overlooked by foreign visitors despite its ancient sites and hospitable small towns. Along the region's mountainous border with Spain you can tour a series of age-old castles and fortified villages, once the first line of defense against foreign invaders.