Puglia is the heel of Italy's boot, and is one of its most fertile regions. The terroir is superbly suited to wine-making and the Primitivo is one of the most highly regarded red wines produced there. To further enhance the concentration of this wine, the method of sun drying grapes is used to reduce the water content of the grapes and allow the rich sugary juice to react with yeasts during fermentation. This method is also used during the production of the famous Amarone wines and I think you can see some similarities. Southern Italy is traditionally a poorer part of the country, so the emulation of the technique means you end up with a wine that has many of the hallmarks of a premium Italian red at a fraction of the cost.