Between Bordeaux and Rioja is the coastal area of Basque Country. Whenever (literally whenever) we mentioned the area of Europe we were going to, every single person asked, "Are you going to San Sebastian?" OK. In addition, our neighbor is Basque so we got some inside tips to begin with. We made sure that was our base of operation for a few days. Nice.
We happened to get there during the Basque Week (week+) of celebration called Euskal Jaiak which may or may not have added to the atmosphere. It seemed like no one slept at night given the time locals show up for dinner (9 to 11 arrivals!), but we made sure that even if we arrived at 8:30 (and were usually in the first 5 groups to be seated), we were never the first to leave the restaurant. Jill will (eventually) talk about all the great food (amazing) so I won't go into that.
There was a regatta in the ocean/bay (Regatas de la Concha) where local towns each have an entry each year in a 20 minute out and back boat race that brings tremendous crowds and bragging rights for the year. We saw some time trials on the day we arrived and it was crowded. It turns out that on our last full day were the semi-finals. We happened to have a hotel room overlooking the bay so we were able to watch it live above the beach AND watch the TV version simultaneously. The crowds were amazing and it was fun seeing all the boats watching this follow in the second heat from our room. The bay was packed with boats.
The town reminded me a little of New Orleans by the party atmosphere particularly in the Old Town area. Fortunately we could walk there in 10 minutes but we were down along the beach. We did have a close nightclub pounding away until 4 or 5 every morning (except Sun night / Mon morning). It made for light sleeping, but the crashing of the waves was very pleasant throughout the nights. This was relaxing and a nice break from winery tours.