Perista is perched upon a rather steep slope of Xerovouni, a mountain whose eastern face looks over the vast green depths of the Patras sea. The mountain is located in a region known since Roman times as Kravara - named as such for its rockiness. ("Gravus" in Latin means heavy, something that cannot be lifted.) On its eastern face, Xerovouni is barren, lacking in the growth of trees and shrubs. But on its other faces and on areas closest to its base, grow many different species of trees and other forms of plant life. One particular plant grows there, more precious than all the others. It blooms and May and is ripe for picking in June. It is the plant from which mountain tea is obtained, and it was valuable because it served the villagers as a panacea for all sorts of illnesses. The lush green portions of the mountain are also characterized by the plentiful flow of fresh water; streams branch out and crisscross over Xerovouni's slopes, quenching the thirst of plants, animals, and humans alike. Directly above the village lies a thick curtain of forest, providing ample food for grazing sheep and goats.

The naked, weather-beaten peak of Psoriari rises to the west of Xerovouni; the two mountains are connected by the small hilltops of Aghia Sotira, which rise between them. It was originally nicknamed "Psoriari" (it means "to suffer from scabies" or "to be covered in rags") because the mountain soil was infertile and poor in quality, but the unfortunate name stuck.

The mountain upon which the village of Perkos rests is slightly lower, but in the same range as, Psoriari. The territory of Perkos is divided from Perista's by a deep ravine called Kakkavos. The ravine carries fresh cold water, derived from the melting snow and ice at the mountain top, and it tends to overflow during raging winter storms; it empties into the river Fidaris (also known as Evinos) down below. The source of the river Fidari is in the northwest region of Bardousia, and its name is derived from its snakelike curves (Fidi=snake). Its mouth lies near the historical city of Mesologgi, in the gulf of Patras. Besides the Kakkavos between Perko and Perista, other ravines that conduct water into the Fidaris include the Vrostiani ravine, the Stiliorema, the Kastania, the Skotini of Pelista, the Klepas, the Kakkavos of Sinista, the Kakkavos of Koutoulistia, and the Votsaitikos Kakkavos ravines.

Aninos, a mountain about 2,000 meters in altitude, towers over Perista in the north, and a number of unexplored caves lie gaping at its base. Central portions of its slopes are barren also, and reflect the light of the sun, thanks to the dark blue color of the granite in its rocks.

The village itself is located in one of Greece's most mountainous regions. The village square resides at an altitude of 850m. Xerovouni is at a height of 1,575m., Ano Melokedra 1,384m., Psoriaris is at 1,404m.,Agiasotira at 1,120m., Ai-Lias at 1,100m.

Aninos at whose base lies the river Evinos, rises to an altitude of 1,703m., Arapokefala has a height of 1,716m., Sarandena reaches 1,610m., and Karfopetalias 1,500m. Other tall mountains in the area include Alonakis with an altitude of 1,422m. and Ardini with 1,703m. Also in the area is the mountain of Apodotia (also known as Papadia), whose highest peak has an altitude of 1,714m. the village of Lombotina (Ano-Hora) lies at the foot of the mountain. Nearby lies the village of Trikorfo with an altitude of 1,736m.

Due to the steepness of the slope upon which Perista is located, the soil can only be contained for cultivation by man-made plateaus. The soil itself tends to be reddish in color, and contains an wide variety of minerals, but is poor when it comes to large-scale agricultural production. The territory of Perista extends to include about 12,000 acres in all.