on this site before, though I wrote about a white wine produced from the grape. Since I wrote that post, I've found that there are some white wines made from the Xinomavro grape, but the most exciting examples are universally red.
Xinomavro is found mostly in the Imathia subregion of Macedonia in northern Greece. Within Imathia is the town of Naoussa where the best Xinomavros are made. It can be a little tough to find Xinomavro wines because the grapes is not usually mentioned on the label, but rest assured if your label says "Naoussa" then you're in very good shape as this area is a monoculture and does not produce wine from any other grape. The name Naoussa is a Greek corruption of the Roman name for the village, "Nova Augusta," and the region has produced wine for thousands of years. When the Ottomans took over Greece, the townspeople of Naoussa were able to negotiate some particularly favorable deals with them and they were able to keep and maintain their vineyards for the duration of the Ottoman occupation (since the Ottomans were Muslim, many regions in Greece were forced to abandon wine production in order to comply with Ottoman religious custom). Political struggles between local leaders and a disastrous revolt against the Ottoman occupiers in the early part of the 18th Century were major setbacks for the region as they exacted serious financial, territorial and human tolls on the region. They've since rebounded nicely and the region was given Appellation status in 1971.
Xinomavro itself is a finicky grape to grow. It doesn't like very dry conditions, is susceptible to several fungal diseases, and is very sensitive to soil types, planting densities and canopy management. There are also many different clones of the grape which differ markedly from one another in virtually every way that you can think of. They flower and ripen at different times, have different bunch and berry sizes, have different vinous characteristics (fruit, acidity and tannin) and reach their peak ripeness in different microclimates. No one clone seems to have the magic combination so many different clones are grown on different sites and blended together in the winery. Once you get past all the growing troubles and issues in the winery (many clones have poor color stability and can create very odd aromas when vinified), the wine that you get tends to be fairly light in color and very high and acidity and tannin. In short, it is the polar opposite of the kind of wine that is very much in fashion right now in that it's not very accessible in its youth and tends to demand food. Needless to say, Xinomavro is facing several uphill battles in the world marketplace.