The winery of Tetramythos is situated near Ano Diacofto, whilst the vineyards are amongst the nearby villages of Aegialia in the wine region of Patras (Achaea). They are ranged between 450 – 1,000m on the slopes of Mount Aroania, where breezes from the gulf of Corinth assist in creating a microclimate that results in fine quality grapes. In classical times Pausanias referred to the villages of Aegialia as ideal for the cultivation of grapes.

Tetramythos was founded by the brothers Aristides and Stathis Spanos, whilst another native of the area, Panagiotis Papagiannopoulos, joined them in 1999 as wine maker. The vineyards were extended in 2003 and a modern winery built and equipped the following year. Today they operate organically, focusing on the native black varieties of Mavro Kalavrytino (the ski resort of Kalavryta is just up the road), Agiorgitiko, as well as the native white grapes of Roditis and Malagousia. They also grow Sauvignon Blanc, Merlot and Cabernet Sauvignon.