Kato Lοusoi Kalavryton is one of the highest villages in the Peloponnese on the slopes of a captivating plateau of Mount Helmos. It owes its name, like its neighboring village Ano Lousoi, to the ancient Arcadian city of the same name. Ruins of the ancient Lousas, and especially of the temple of Artemis Day or Imerasia, are preserved to this day near the village.

The area was well known in antiquity because of the legend of the healing of the Proitides by the seer Melampodas. The sinkholes of Louso and the Cave of the Lakes are connected with the same legend. The old name of the village was Sudena, which means cold place and recalls the place of origin of the first inhabitants of modern times from Sudena (Pedina) in Epirus.

In the Revolution of 1821 the inhabitants of the village gave a strong presence in the fight against the Ottomans led by the historical family of Petmezai. The Petmeza tower, which is a landmark for the area, is preserved to this day in good condition and is in a prominent position within the village, and the central square with the centuries-old plane tree bears their name.

But also the houses, all built with the untouchable technique of hewn stone, the threshing floors, the fountains and the gardens, together with the few hospitable people make up an enchanting landscape.