The Parnonas range is the longest mountain range in the Peloponnese. It extends for 70km from north to south, running from the Plain of Tegea near Tripolis to the village of Yeraki in Lakonia, and from the Evrotas valley in Lakonia in the west to the shores of the Argolic Gulf in the east.

The highest peak, Megali Tourla or Parnonas, is clearly visible from Paralio Astros. At a height of 1,936 metres above sea level, its characteristic outline dominates the view to the west from everywhere in the village.