Perhaps the most picturesque of all international cities, Paris is the quintessential walker's paradise, with architectural delights down every winding street. It is the city of the Eiffel Tower and the Arc de Triomphe, of the Louvre and Monmartre. But, within its 20 concentric arrondissements are many surprises too, from glass office towers to jewel-box mansions to massive public buildings. The monuments, private houses, museums, hotels, and myriad...