States of Austria arable terrain. The other five states, in contrast, are located in the Alps and thus are comparatively unsuitable for agriculture. Their terrain is also relatively unfavourable to heavy industry and long-distance trade. Accordingly, the population of what now is the Republic of Austria has been concentrated in the former four states since prehistoric times. Austria's most densely populated state is the city-state of Vienna, the heart of what is Austria's only metropolitan area. Lower Austria ranks only fourth with regard to population density even though it contains Vienna's suburbs; this is due to large areas of land being predominantly agricultural.
Unincorporated territories of the United States a land area of approximately containing a population of approximately 4 million people; Puerto Rico alone comprises the vast majority of both the total area and total population. Of the 13 territories, five are inhabited. These are either organized or self-governing, but unincorporated. These are Puerto Rico, Guam, Northern Mariana Islands, U.S. Virgin Islands, and American Samoa. There are also nine uninhabited U.S. possessions, of which only Palmyra Atoll is incorporated. (See Territories of the United States, Unorganized territory and insular area.) All modern inhabited territories under the control of the federal government can be considered as part of the