In Argolis is Kefalari. On the northern border of the “Plain of Argos”. Near Peloponnese, at the Argolic Gulf. . It was a significant neolithic era spot. Not far from the area was the pyramid of Hellikon. Experts agree it was probably built around 4000 years ago. Though hard to carbon date the stones, there are many other significant archaeological finds. Included in stories of neolithic era history, and remains from the area. Here’s some info about the unique and abundant Greek region. During neolithic times, Tens of thousands visited and developed around the large natural karst spring. Even in mythology, there are stories of ancient Greeks at these springs. It is significantly important to what we study today. To many, spring, lit, or gushing abundant water, is a place of Greek orthodox pilgrimage.

Kefalari mythology describes Hercules, Hydra and the area
Stories describe how Hercules eliminated the mythical monster Hydra near the region Lerni, in modern-day Myloi (Argolis). He killed it, then buried the main head of the Hydra above a small mountain named Chaon (Argolis). After that, a large spring mushroomed, providing water in abundance to the people of Argos. The actual meaning of Kefalari (Κεφαλάρι) derives from the words αἴρω + κεφάλι (lift/cut + head) taken from the mythical fight of Hercules and Hydra.
Kefalari was an integral part of the ancient city-state of Argos.

Geography
It is a small community. Argos, the next closest big place with significant population is approximately 6 km (3.7 miles) away (map).
In the community large quantities of water, from the subterranean waterways, emerge in a large karst spring. It is where the carbonate mountains end, and the fertile plain of Argos begins. The waters run into the river Erasinos, and towards Argolic Gulf. There are many platanus trees and the region is quite beautiful (pic).
60m above the Kefalari spring, there is a cave. People used to chill here more. Nowadays in the spring sometimes the water will run low. Especially in the dry season. Unfortunately, many people will not drink the water anymore because it makes them sick.

At the Hellikon Pyramid archeological site nearby, are the remains of a 20 or 30 foot square pyramid.
Modern-day Kefalari is still a small, lovely village and popular vacation spot. Check it out, with some more neolithic architecture today.

Bibliography: Greek travel pages: “KEFALARI Village ARGOS”

William Smith: Dictionary of Greek and Roman Geography, London (Walton and Maberly) 1854