Donostia/San Sebastián, Spain

One name isn't enough for this resort city in Northern Spain on the Atlantic Ocean. You need two of them. San Sebastian works for the Spanish population, but for Basques it is called Donastia. 

It's a nice-sized city, checking in at about 450,000 people, and it overlooks the Atlantic Ocean on the Bay of Biscay. The ocean keeps things mild and a bit rainy. The average high in the summer is below 80 (although it has cracked three digits at times), and the average low in the winter is above 40. That sounds about right.

There's the usual Old Town fairly close to the water, and it seems to be the center of activity. San Sebastian is a cosmopolitan area too. There are a variety of cultural festivals staged here over the course of the year, including ones in film and jazz. 

Oh, and the coastline looks good no matter when you visit.