Mountain Paiko or Pajak in Bulgarian is a small mountain range that lies on the border of the Pella and Kilkis regional units in Central Macedonia, Greece.

Pella is one of the regional units of Greece, in the geographic region of Macedonia. It is part of the Region of Central Macedonia. It is named after the ancient city of Pella, the capital of ancient Macedonia and the birthplace of Alexander the Great. The capital of Pella is Edessa with a population of 19,036 inhabitants according to the census of 2021, while the largest town is Giannitsa. Other towns include Aridaia, Skydra, Arnissa, Exaplatanos and Krya Vrysi.