The municipality Γρεβενά was formed at the 2011 local government reform by the merger of 13 former municipalities that became municipal units, including Ζιάκας.
The municipality's population (2001 census) is 30,564.
Περιφερειακή ενότητα Γρεβενών is a regional unit in Δυτική Μακεδονία (West Macedonia).
In 1983, Γρεβενά was a so-called νόμος (nómos, department), which is the area indicated dark blue on the map.
Ζιάκας is a municipal unit of the municipality Γρεβενά. Before the 2011 local government reform, the village itself constituted a municipality. The population (2001 census) is 1,723 (village) and 2,855 (all settlements in the municipal unit).
Ζιάκας (altitude 900 m) is south west of Γρεβενά. Distance from Γρεβενά is 22 km, from Σπήλαιο (Spíleon) 4 km. On the
hill facing Ζιάκας are the tiny villages Μαυραναίοι (Mavranái) and Ανάβρυτα (Anávrita).
On this map you can clearly see the road from Γρεβενά to Ζιάκας as described in October 1983. It is part of a (wandplaat) which I bought in 1983, hence the name "Zákas".