Between La Rioja and the city of Pamplona lies the wine region of Navarra, one of the oldest in Spain. The main grapes used for red wine are Garnacha (known as Grenache in France) and of course, Tempranillo. Over recent years Navarra has suffered a low profile as other regions have forged ahead. Two wines to look out for, though, are Gran Feudo from Bodega Julian Chivite, and Irache from the bodega of the same name. As a matter of interest, the Irache bodega lies on the Camino de Santiago, the great pilgrim route that enters Spain from France at Roncesvalles in the Pyrenees and crosses northern Spain to arrive finally at the Galician city of Santiago de Compostela. For the convenience of passing pilgrims Irache offers a drinking fountain in the wall of the bodega with two taps, one dispensing water, the other red wine.
The other red wine region to consider is Aragón, which divides into four sub-regions. Aragón lies at the foot of the Pyrenees between Navarra and Cataluña. It was the kingdom of Ferdinand, who married Isabel of Castille, and together they completed the Reconquest of Spain, taking Granada from the Muslim rulers on 31st December, 1492, and gaining for themselves the title of "Los Reyes Católicos" (The Catholic Monarchs).
The most northerly of the sub-regions is Somontano, east of the city of Huesca. Its proximity to France has led it to plant Cabernet Sauvignon, Merlot, Pinot Noir and Syrah alongside the traditional Garnacha and Tempranillo. A Somontano red that can be recommended is Enate.
The other three sub-regions lie further to the south near the city of Zaragoza. All produce good, serviceable red wines mainly from Garnacha, though with some Tempranillo. Old vines Garnacha can result in some very good everyday, quaffing wines. Campo de Borja, west of Zaragoza has Coto de Hayas. Incidentally the Borjas were known in Italy as the Borgias. Calatayud, to the south of Zaragoza has no outstanding wines to offer, but if you see Calatayud on the label and the price is reasonable, give it a try and see what you think. Finally, Cariñena is a bit of a contradiction. It is the name, not only of the sub-region, but also of its indigenous grape - which it virtually ignores preferring Garnacha. The wines are mainly Joven, but a label to look out for is Corona de Aragón.
And that really is about it so far as Spanish reds are concerned, except to say that surprisingly, given the climate, my own communidad of Andalucía has begun to produce quite decent red wines. From the Province of Cádiz there is Barbazul, a powerful 15% abv!In Granada Province, Bodegas Señorio Nazarí offer Delirio and Muñana Roja, and Málaga Province, too, has its offering. However, all of these are small producers and you are unlikely yet to find any of them outside Spain. Still that's a good excuse to come visit.