In the shadow of the imposing Chelmos mountain, in the middle of a plane-tree forest and through the roots of a rock gush the waters from the springs, which form the little Aroanios river. The springs of Aroanios are located in the southwest of Chelmos, at an altitude of 700 meters, next by the Planitero village. The etymology of the name Planitero (plane trees and water) prepares you for the landscape you will encounter. The two main tributaries that descend from Chelmos and form the Aroanios river, Chaliki and Kefalovrysos stream are joined near the springs. The bulk of the water, however, comes from a spring-lake located at the root of a big rock. The flow is impressive, while the waters come from both Chelmos mountain and Feneos basin through sinkholes. Aroanios river continues south to the valley of Katsana and flows into Ladonas river, covering a total length of 10 km. Close by the springs are old water fountains and watermills, restaurants, stalls with traditional products and trout farms. So one can enjoy the pictures of wildlife while enjoying his coffee or food. Because of the constant human presence, many species of birdlife are rather courageous and allow you to admire them from a close range. Although the intense tourist development has altered the naturalness of the landscape, the area still holds its wild beauty. It is also worth making some stops to explore the open planes around the Planitero, as they are full of rare species of the Peloponnesian flora.
Around the springs lies a dense forest of oriental plane-trees that covers an area of 30 acres. The trees grow on a plateau between a labyrinth of water meanders and many trees reach a diameter of 4 meters. The forest is protected from the east by vertical rocks on which various interesting species grow. The most important species in the surrounding area are Aurinia moreana, Asperula arcadiensis, Onosma erecta subsp. malickyi, Campanula topaliana subsp. topaliana, Centaurea affinis subsp. laconiae, Inula verbascifolia subsp. methanaea, Verbascum daenzeri and Crocus olivieri subsp. olivieri. More common species are Digitalis laevigata subsp. graeca, Iris unguicularis subsp. angustifolia, Asyneuma limonifolium subsp. limonifolium, Primula vulgaris subsp. vulgaris, Geranium purpureum, Lunaria annua subsp. pachyrhiza, Melitis melissophyllum subsp. albida, Sedum album, Sedum laconicum subsp. laconicum, Sternbergia lutea subsp. lutea, Viola alba subsp. dehnhardtii, Viola riviniana, Adiantum capillus-veneris, Petrorhagia glutacea, Centaurea cyanus, Epilobium hirsutum, Epilobium obscurum, Teucrium capitatum subsp. capitatum, Chamaecytisus hirsutus subsp. hirsutus, Draba muralis, Silene graeca, Equisetum ramosissimum, Dianthus viscidus, Gagea villosa and Galium verum subsp. verum. The orchids here are Dactylorhiza saccifera, Limodorum abortivum, Ophrys mammosa, Ophrys delpinensis, Ophrys apifera and Ophrys hebes.
Bird watching in the area is a total pleasure. Wood nuthatches and short-toed treecreepers are searching fearlessly for food on the trunks of trees and grey wagtails are pecking at the banks. The springs still hold a small population of dippers, which is a rare sight for the Peloponnese. From the predators in the area live short-toed eagles, common buzzards, honey buzzards, sparrowhawks, levant sparrowhawks, peregrines and kestrels. The cavities of the plane trees host tawny owl nests and in the surroundings live little owls and scops owls. The area around the plane trees are ideal for woodcocks that come here looking for earthworms. Other birds are sandpipers, woodpigeons, turtle doves, cuckoos, swifts, alpine swifts, bee-eaters, middle spotted woodpeckers, woodlarks, swallows, red-rumped swallows, house martins, water pipits, wrens, dunnocks, robins, nightingales, redstarts, blue rock thrushes, song thrushes, blackbirds, blackcaps, lesser whitethroats, subalpine warblers, orphean warblers, wood warblers, spotted flycatchers, semicollared flycatchers, blue tits, long-tailed tits, jackdaws, chaffinches, goldfinches, greenfinches, serins, siskins, cirl buntings and rock buntings
From the amphibians here live fire salamanders, greek newts, toads, green toads, balkan frogs and greek frogs. The rich herpetofauna of the region is represented by Hermann’s tortoises, peloponnese slow worms, greek slow worms, glass lizards, mediterranean house geckos, greek algyroides, greek rock lizards, balkan green lizards, common wall lizards, peloponnese wall lizards, balkan wall lizards, snake-eyed skinks, smooth snakes, four-lined snakes, balkan whip snakes, levant montpellier snakes, grass snakes, leopard snakes and nose-horned vipers. There have been local reports that otters still live in the Ladonas-Aroanios rivers system. The area is important for bats as it is full of caves. Here live species such as common bent-wing bats (Miniopterus schreibersii), lesser mouse-eared bats (Myotis blythii), long-fingered bats (Myotis capaccinii), greater mouse-eared bats (Myotis myotis), mediterranean horseshoe bats (Rhinolophus euryale), greater horseshoe bats (Rhinolophus ferrumequinum) and Mehely’s horseshoe bats (Rhinolophus mehelyi). Other mammals include foxes, weasels, eastern hedgehogs, hares, forest dormouses and grey dwarf hamsters. In the waters of the river live the invasive rainbow trout (Oncorhynchus mykiss) that have escaped from fish farms and species such as the peloponnese barbel (Barbus peloponnesius), the epiros riffle dace (Telestes pleurobipunctatus) and the peloponnese chub (Squalius peloponnensis).