The Central Balkan band seems to have several pyramidal formations that act as relay stations between the sites on the North and South side of the mountain range.
This band requires further investigation.
The megalithic sites of the Central Balkan like Maragidik, Kupen and Yonkova Mogila seem to tower above the valleys below. Kupen seems to be the central point even though it is not the highest summit of the mountain range.
The pyramidal formations are heavily eroded which means that we can distinguish the overall outline of the pyramids but the summits and detail seem invisible up close.
Sites like Yonkova Mogila seem to be built on a matrix of rectilinear stone blocks and rubble that uncannily remind us of the Roman building technique of stone, brick and mortar that can still be seen at medieval churches and mosques in Plovdiv.
Many of the larger stones are made from granite.
We also find limestone that contains no quartz.
The Central Balkan band includes
A pyramidal formation that connects to the Double Pyramid of Ostrets to the North and the many megalithic sites on the South side of the Central Balkan.
A pyramidal formation that stands on the west side of the highest summit of the Central Balkan mountain range.
A pyramidal formation where the underlying structure looks like the brick, stone and mortar technique used by later Romans.