What is the fine-grained topic of the following text: The Garnacha Tinta is selected from vineyards located in Rioja Alta, specifically Cenicero and Nájera, with respective altitudes of 650m and 500m, so as to achieve finesse, freshness and, at the same time, good structure. Only return the topic.
Selection and location of Garnacha Tinta vineyards in Rioja Alta