Asparuhov Val (Varna)

 park, 1935_construction

The embankment of Asparuh is a surviving testimony to how the Proto-Bulgarians used to strengthen their borders.
It is believed to be built in the 8th century to protect the lower coast from sea invasions, most likely from Byzantine Empire.
As good warriors, the Proto-Bulgarians knew the tactical value of height in the midst of the battle. In the lower part of the embankment of Asparuh above the solid main part of compacted gray-black clay sand or stone masonry sand or clay sand mixed with a small amount of stone-brick was placed. The embankment's upper part consists of a coating of clay sand mixed with mortar and a large amount of stones and broken bricks. Swamps are still observed around the shaft and apparently this "embedding in the rocks" was done to overcome them. Without this, it was impossible to spread and compact the first layers of the embankment. The ancient Bulgarian builders took special care to strengthen the body of the embankment.
When the deep sea-lake canal was dug in 1976, embankment of Asparuh was divided into two parts and the southern part of it can be seen in Asparuhov Park.

visit.varna.bg/en/asparuhov-val.html
www.varnaheritage.com/en/archeological/staroblgarski-uk...