The Monastery of Timios Prodromos (meaning "Prodromos the Fair"), is located at the center of Parnon, and is built atop an enormous rock at an altitude of 937m above sea level. Its monks managed to build its first structures inside the rock. The view from the monastery is unique, as it is located above the canyon of the river Tanos. It is located near the village of Kastri, Perdikovrysi, and it was originally a monastery for men. Based on the inscription of a witness, it was built in 1126 and renovated in the 18^th century. It is therefore considered one of the oldest monasteries of Peloponnese.

Its katholikon was originaly 12 square meters in area, along with its altar in the northeast side. It was also built at the entrance of a cave. Essentially, the katholikon is a cavernous temple at a higher level than all the other structures (on the second floor). An impressive wood-carved iconostasis inside of the temple is very distinguished. The monastery also contains many murals, which unfortunately have not been preserved well. There is a long passageway next to the katholikon, which leads to "Spileo tou Panos" ("The Cave of Panos"). This passageway, according to folklore, reaches the Monastery of Malevi. Nowadays, the entrance to the cave from the katholikon has been closed off. The monastery contains two crypts, meaning two underground tunnels that visitors can reach from the kitchen.

In its centuries-long history, the monastery has undergone many changes. Its cells form the Greek letter "Π". Its two towers were built in the mid-14^th century, one to the south and one to the north of the complex. There is a large garden in the middle, and also the “Cave of Prodromos” (Greek Name: “Spileo tou Prodromou”), deep inside the monastery, which was the ultimate place of refuge in case the area was invaded by enemies. During the Greek Revolution, the garden was used many times as a make-shift hospital by and for the soldiers. In 1826, the monastery managed to successfully repel the attack made by Ibrahim Pasha's regiments, and thus forced them to retreat.

It was converted into a monastery for women in 1980. In 2002, parts of the monastery underwent renovation.

It celebrates every 6^th and 14^th of September, also a date for the Feast of the Cross. It also hosts a grand festival every 5^th and 6^th of September.