Discover the colorful history of Retz, a city whose wealth and culture is built around the wine trade. Three levels and 14 miles of wine cellar tunnels comprise a complex network under the city. Deep below the cobblestone-paved square, a complex web of wine cellars carved out of deep-sea sand sediment await your exploration. A tour through the "Erlebniskeller" guides you through a portion of these ancient tunnels and reveals fascinating details about the city's wine trade. Although the people of Retz had been making wine and digging cellars since the village's foundation in 1278, citizens were granted the right to trade wine only in 1458 by Emperor Friedrich II, and the tunnels began to expand. At the peak of Retz's involvement in wine trade in the mid-18th century, more than 2 million liters of wine were stored in these cellars. At the end of the mind-blowing 1½ hour tour through these catacombs, you resurface in the Vinothek of hotel Althof where 130 wines from the surrounding vineyards are available to taste and bring home..