until recently been predominantly
agricultural. Industrialization was undertaken late, and it was not
until 1969 that the urban population equaled that of the rural areas
(see ch. 2).

NATURAL FEATURES

Topography

Alternating bands of high and low terrain extend generally east to west
across the country. The four most prominent of these from north to
south are the Danubian plateau, the Stara Planina (Old Mountain), or
Balkan Mountains, the central Thracian Plain, and the Rodopi (or Rhodope
Mountains). The western part of the country, however, consists almost
entirely of higher land, and the individual mountain ranges in the east
tend to taper into hills and gentle uplands as they approach the Black
Sea (see fig. 2).

The Danubian plateau, also called a plain or a tableland, extends from
the Yugoslav border to the Black Sea. It encompasses the area between
the Danube River, which forms most of the country's northern border, and
the Stara Planina to the south. The plateau rises from cliffs along the
river, which are typically 300 to 600 feet high, and abuts against the
mountains at elevations on the order of 1,200 to 1,500 feet. The region
slopes gently but perceptibly from the river southward to the mountains.
The western portion is lower and more dissected; in the east it becomes
regular but somewhat higher, better resembling a plateau. Bulgarians
name local areas within it, but they do not name the region as a whole.
It is a fertile area with undulating hills and is the granary of the
country.

The southern edge of the Danubian plateau blends into the foothills of
the Stara Planina, the Bulgarian extension of the Carpathian Mountains.
The Carpathians resemble a reversed S as they run eastward from
Czechoslovakia across the northern portion of Romania, swinging
southward to the middle of that country, where they run westward and
cross Romania as the Transylvanian Alps. At a famous gorge of the Danube
River known as the Iron Gate, which forms part of the Romania-Yugoslavia
border, the Carpathians again sweep eastward, becoming Bulgaria's Stara
Planina range.

Considered in its local context, the Stara Planina originates at the
Timok Valley in Yugoslavia, continues southeastward as it becomes the
northern boundary of the Sofia Basin, and then turns more directly
eastward to terminate at Cape Emine on the Black Sea. It is some 370
miles in length, and some twelve to thirty miles in width. It retains
its height