Located on the Rhine River near the borders of France and Germany, Basel contains the country's highest concentration of museums. The culture-centric city, site of the world's most influential art market each June, is also home to the lovely Munster Cathedral, made of red sandstone with a multi-colored tile roof. Green spaces abound, including the popular zoological gardens in the city center. Switzerland's largest site of Roman ruins, Augusta Raurica, are an easy day trip to the east.