The Shumen Reservoir, a small artificial lake for irrigation and recreation.
The smaller lake in the background is the Dibich Reservoir. (Dibich is a small village very close to Shumen.)
This image is a composite of two photos taken from an observation spot on the Shumen Plateau. The reservoir was too large to fit in one image when zoomed in. :)
Stitched with Hugin, rectilinear projection.