Constructed of earth and wood, they had ramparts and palisades that stretched for up to half a mile, and were laid out in a manner that suggests spiritual and astronomical significance (Google translated German site). They appear to be alligned and designed in a similar manner, They were built by a religious people who lived in communal longhouses up to 50 metres long, grouped around substantial villages.
The people who built the huge circular temples were the descendants of migrants who arrived many centuries earlier from the Danube plain in what is now northern Serbia and Hungary. The temple-builders were pastoralists, controlling large herds of cattle, sheep and goats as well as pigs. They made tools of stone, bone and wood, and small ceramic statues of humans and animals. They manufactured substantial amounts of pottery decorated with geometrical designs such as spirals and triangles, had flint sickles polished stone hatchets, and and they lived in villages with large longhouses.
Their civilisation seems to have died out after about 200 years and the recent archaeological discoveries are so new that the temple building culture does not even have a name yet.
The same archeologists recently discovered (trans.) what appears to be the oldest male clay figurine in Europe (.pdf), which dates back to the same time period.
The researchers have also previously found numerous female figurines with large breasts dating back to the same time period, along with pots decorated with human and animal forms and pottery. Based on the figure of the adonis, there is strong suspicion that this culture was based on some kind of fertility-based spirituality.