Mainalo (1,981m) [P-1215]
Summited On: April 12, 2025
Region: Arcadia, Peloponnese, Greece.
Introduction
With a rare dry mild-weather window this April we decided to not let the opportunity go to waste and headed South to Arcadia prefecture in the Peloponnese, to hike the rather easy summit of Mainalo (1,981m), the “central” mountain of the region. Its location and sub-2k elevation make it somewhat unpleasant to attempt during the hot dry months, and that coupled with Nieve’s recent skiing injury, it was time to finally give it a go.
Viewing the Ostrakina Massif from the East, traditionally the way into Mantinea Plain from Athens, one would be forgiven to be taken aback with the beauty of the scene. The steep limestone cone of the summit, some 1,300m above; and for more then 1,000m, holding onto the steep slopes, are countless fir trees [1], emanating a deep green hue in the morning light. For its appearance however, is only slightly deceiving, because luckily for us, the massif has a small valley, 1,650m above sea level, at which we normally ski at, but today we were to be hiking from.
The Ostrakina Massif in the background from Ancient Mantinea, the ruins of the theater visible in the foreground.
In Greek mythology the mountain is closely associated with the Arcadian tribes and their worship of the god Pan , a protector of shepherds and master of the low laying but nevertheless steep hills of Northern Peloponnese, which the tribes called home [2]. The quintessential imagery attached to his cult, grassy slopes, dense forests, bees, flowers, and water galore, are real, and the dominant nature of this still wild range. Its Karstic geology is a real highlight, imbuing life very literally from the ground up by storing, filtering, and transporting water. Interestingly enough, the Mantinean’s believed that their city was the birth place of Poseidon, and considered him their protector [3], for they literally lived on water. Today the plain is the home of the Protected Designation of Origin (PDO) “Blanc de Gris”, for the local Rose wine of the Moschofilero grape variety [4].
Ancient Mantinea was one of the largest in Arcadia, with extensive fortifications and the little known Dam of Mantinea - a classical engineering marvel - supporting the drainage of water towards what is today Kapsias Cave.
Ostrakina (1,981m)
Looking East, or just up, form the Mainalo Refuge (P. Alexopoulos) at 1,634m of altitude, a few hundred meters South of the Mainalo Ski Center, the summit cone of Ostrakina (1,981m) dominates the skyline. The hike up the ~430m of elevation to the summit is trivial, although at points exposed, and is well recommended for beginner and intermediate hikers looking for their first foray into summits. The trail is about 2.5km one-way and a mere hour to ascend. For us this meant we were more than welcome to take our time and fully indulge myself into some geology, and surprisingly entomology.
View of Mainalo alpine peaks to the W-NW from Ostrakina (1,981m).
For the sake of completeness I will now discuss the route. Starting from the refuge and going E with the forestry road, the hiker should follow the yellow markings starting from the first hairpin of the road, going directly for the peak’s shoulder. From here the trail is narrow and travels in-between young vegetation and exposed rocks. Approaching the first half (30 mins) the trail breaks above the tree-line and travels N-NE for a bit, avoiding bands of limestone at around 1,750m. Here the trail turns S and the traverse begins, crossing all the way to the south ridge. This section is not as steep but becomes exposed for a brief moment in the middle of the face, and just above 1,890m begins to travel directly E towards the ridge. In the next 10 minutes the summit ridge will have been reached at 1,950m and the last 30m of elevation are made hiking N, up the summit pyramid. At a standard pace it should take just about 1 hour from refuge to summit.
Splitting Rocks with Ice
A split limestone block near the Ostrakina ridge
As the trail proceeds towards 1,850m, where snow cover is more extensive throughout the year, a series of peculiar limestones piqued my attention. So far up, the terrain was traditional to Hellenic limestone, scattered massive blocks and outcroppings, clear water weathering, and their usual grey color [5]. Nearing the ridge blocks of split limestone, distanced between them, were scattered along the trail. Being in Greece my mind instantly went to fault processes, especially considering the clean cuts, but it was something more intriguing, and dare I say insidious, ice. Interestingly enough, I have not seen, or maybe just not noticed, such split rocks at elevations much higher than here across Greece. These curiosities are probably also driven by another factor.
It is likely that the cracking process was sped-up by the fact that these rocks where rotated 90-degrees from their original deposition, with the bedding facing the sky and the rain able to for cracks along the strata (along the grain), and not against.
Ice wedge splitting process diagram.
In fact, these massive splits happened through the cycle of water collection and ice expansion, over not that many (geologically) years. When a container - here a slit in a rock - is filled with water, and then frozen, the volume of the ice is increased by 9%. Over many cycles of expansion, a wedge is created, eventually splitting the rock, ‘opening’ the original crack and stopping the water collection process altogether [6]. Here, at +1,900m of elevation, many are the boulders which have met this fate.
What is a Nivation Hollow?
It was no more than 50 steps from our last split rock inspection that the ridge gave way to exceptional views into the largest Polje (a karstic plain) of Arcadia, 1,300m below our feet. Here a depression on the eastern side of the ridge opened up like a hanging valley into the 1km tall cliff right in front of us. What a curious sight, as hanging valleys are generally associated with Glacial retreat; were there glaciers here?
The Ostrakina Nivation Hollow / Hanging Valley. The Mantinea Polje bellow it.
Glaciers are known to have existed throughout Greek mountains during the Late Glacial Maximum (LGM), but there is very sparse evidence to point to such a situation on Mainalo, even though glaciation took place nearby at similar elevations, although on mountains with higher maximum elevations [7]. A quick look at the curiosity offers enough information to conclude that this is probably not of glacial origin. The telltale signs, those of a steep cirque, large erratic boulders, and a moraine, are all missing. What is certain is that the lack of any large surface rocks points towards a wet erosion system.
What we are looking at here is probably a Nivation Hollow, an indentation into the terrain driven by persistent snow-patches, as still visible in the photo in April 2025, which leads to the erosion of areas near slopes; same as seen here. In fact, a paper on Periglacial formations in Slovenia provides us with a helpful diagram [8], which could have just been lifted off from the photo above. So how does it form?
Initially the Nivation area collected snow which was blown across the summit from strong Northern winds, collecting on the leeward side of the summit, right on this ridge. Throughout the season additional snow, falling directly or collected from small avalanches continues to pack the area. Due to its orientation (facing East) it is benefited from very little direct sunlight, thus, maintaining the packed Neve and creating the hollow through erosion.
Summit Ladybugs
Ladybugs on the summit cairn of Ostrakina (1,981m), having just awoken from hibernation.
There was one final curiosity waiting for us at the summit of Ostrakina (1,981m), a curiosity which many hikers may be aware of but not knowledgeable about; summit lady-bugs. Hiking to alpine summits in spring and autumn, visitors will often notice large colonies of ladybugs scattered on rocks; what are they doing here at 2,000m? Truth is, no one is really sure [9]. Ladybugs (Hippodamia convergens) tend to feed and give birth at lower elevations, where they can find and eat Aphids. It is thus supposed that their presence in the alpine is part of a hibernation cycle (diapause) [10]. Specifically, ladybugs are though to live in lower elevations during spring and summer, during which period they feed on Aphids and breed. As winter approaches, the beetles make their way to higher elevations. Here they supposedly find rocks onto which they will winter, spending their time under the snowpack [11]. This is though to be due to the lack of predators and general protection offered. As spring approaches, and the summit rocks are uncovered again, the ladybugs wake up from their slumber, and once the temperature allows, make their way down again, to restart the process.
Because ladybugs freeze at 12C and cannot keep flying, during their ascent to the mountains, they literally fall out of the sky once their body temperature drops to that point. As such their ascent paths look like sinusoidal waves.