The scenic Guadalupe Valley follows the Río Guadalupe between Ensenada [1] and Tecate [2] on Mexico 3, with a small town at Km. 77.
The Valle de Guadalupe is less than a two-hour drive (113 km) south of San Diego on the toll road from Tijuana to Ensenada. After paying the last toll, watch for a sign to Tecate via Mexico 3 and the Ruta del Vino.
Travel east on Mexico 3 for 11 kilometers until you drop down into the Baja wine country at San Antonio de las Minas. This is the western end of the Guadalupe Valley wine region, which extends 22 kilometers east toward Tecate, ending near Km. 73.5 at L. A. Cetto and Domecq wineries.
Links:
[1] http://www.moon.com/destinations/baja-cabo/ensenada-el-rosario/ensenada
[2] http://www.moon.com/destinations/baja-cabo/tijuana-rosarito-and-tecate/tecate