The municipality has a territory of 579.7 km2 (223.8 sq mi), with a population of 17,458, as of December 2009.[1]
More significant tourist sights in the area include the early Byzantinecave monasteries around the villages of Balik and Brestnitsa dating to the 5th-6th century.
The municipality has a mixed population consisting mostly of Turks (40.60% according to 2011 census data), Bulgarians (37.06%) and Romani (11.12%).
The following table shows the change of the population during the last four decades.
Tervel Municipality
Year
1975
1985
1992
2001
2005
2007
2009
2011
Population
28,626
28,717
21,483
18,728
17,995
17,780
17,458
...
Sources: Census 2001,[5] Census 2011,[6] „pop-stat.mashke.org“,[7]
Religion
According to the latest Bulgarian census of 2011, the religious composition, among those who answered the optional question on religious identification, was the following: