The integral nature reserve of Tsingy of Bemaraha lies 60-80 km inland from the west coast in the northern sector of the Antsingy region of the Bemaraha Plateau, north of the Manambolo River Gorge. The additional forests and lakes nominated include all the remaining native forest, mangrove and lakes between the west coast and the Bemaraha Reserve, lying between the Sohanina and Manambolo rivers.
Much of the reserve integral to Tsingy de Bemaraha comprises limestone karst, delimited to the east by abrupt cliffs which rise some 300-400 m above the Hanambolo River valley and extend several tens of kilometres from north to south. The western slopes rise more gently, and the whole western region of the reserve forms a plateau with rounded hillocks which slope away to the west. To the north undulating hills alternate with limestone extrusions, whereas in the south extensive pinnacle formations make access extremely restricted. The Hanambolo River Gorge is on the southern edge of the reserve. Both seasonal and permanent rivers flow on the plateau (draining to the west), and numerous permanent springs arise at the base of the Tsingy on both sides.
Vegetation is characteristic of the calcareous karst regions of western Madagascar, with dense, dry, deciduous forest, and extensive anthropogenic savannahs.
The fauna of the region has not been studied in any detail. The Tsingy is the only known location for chameleon, and the only western dry forest site known for Madagascar grey-throated rail (only previously known from north-western and eastern Madagascar). The reserve is also the only protected area where the endemic nesomyine rodent is known to occur and there is also an unconfirmed report of aye-aye just outside the reserve. Other notable species include goshawk, which may be threatened, and lemur, all of which are (or may be) threatened.
December 1927, and is now protected under Decree No. 66-242 of 1 June 1966. The ancient cemeteries within the Manambolo Gorge, the gorge itself, and the "foreet rochers" (which includes the reserve), are all designated "natural monuments and sites" under a decree of 25 August 1937, all three being listed by an 'arrete' 11 February 1939. However, this latte r designation does not imply any degree of management or protection.