Where at??? My understanding the oldest megaliths in Europe are at malta,and nabta is older than that. THe megaliths ar corinth are not as old as nabta either. Read the article again the megaliths are 6,700-7,000 years old.

If the Megaliths in Nabta are as old as 7000 years old, then that makes them 5000 BC. The Stone circle of Almendres in Portugal date from the same era. You have to do the calculations- 7000 years old takes you to 5000 BC.

http://druidry.org/obod/touchstone/portugal.html

Stone circle of Almendres
This is the largest stone circle of the Iberian peninsula and one of the most important in Europe. It was identified to the modern world in 1964 and the first of its several phases of construction took place in the 5th millennium BC (early Neolithic).