San Marzano tomatoes, a variety of plum tomatoes, are considered by many chefs to be the best sauce tomatoes in the world. The story goes that the first seed of the San Marzano tomato came to Campania in 1770, as a gift from the Kingdom of Peru to the Kingdom of Naples, and that it was planted in the area that corresponds to the present commune of San Marzano. They come from a small town of the same name near Naples, Italy, and were first grown in volcanic soil in the shadow of Mount Vesuvius. The volcanic soil is believed to act as a filter for water impurities. Compared to the Roma Tomatoes with which most people are familiar, Marzano tomatoes are thinner and pointier in shape. The flesh is much thicker with fewer seeds, and the taste is much stronger, more sweet and less acidic. Many people describe the taste as bittersweet, like high-quality chocolate. Because of their high quality and origins near Naples, San Marzano tomatoes have been designated as the only tomatoes that can be used for Vera Pizza Napoletana.