There are many roads that lead to San Sebastian, and - depending on your preferences and budget - you can choose the way that is best for you. You can choose to travel to San Sebastian by plane, or go the scenic route by taking the train or hitting the road.
Yes, San Sebastian is a well connected. By coach, it is only 6 hours away from Barcelona, 5 hours from Madrid, and 1 hour away from Bilbao. Paris is 9 hours away by bus, while it will take 15 hours from London by bus.