In the Alicante area the closest one to the A7/E15 motorway (which is the route you will take from the airport to Altea) is at San Juan and about 1.5km off the El Campello junction. Once you get on the A7/E15 motorway keep on heading north and go through the San Juan tunnel which is about 2km long. Take the very next exit at the end of the tunnel and follow the signs to Alicante/N332. You will see a big Carrefour on the left hand side so either take the slip road on the right and go under the road or continue straight ahead to the next roundabout and come back on yourself.

See this link http://www.carrefour.es/hipermercados/guia_hipermercados/san_juan.html and click on 'ver mapa' to see its location.

The store is open 0900 to 2200.

If you miss that one try the one at Benidorm. Come off at junction 65a and go back about half a mile on the N332. You can then finish your trip to Altea on the N332 (back in the direction you were travelling on the motorway!)

If you don`t manage to find the ones mentioned above or want extras whilst your in Altea. There are a couple of large supermarkets in Albir which is the next town to Altea. Aprox 5/10 mins drive from Altea.