seville
I spent two seperate months of my gap year (October 1999 and February 2000) in Seville at a language school learning some Spanish and seeing the sights. The school I went to was CLIC and it was excellent, as were the teachers (and not they're not paying me to say that!). I went because I knew I wanted to start Spanish from scratch at University, and so went for the head-start in the basics in the language's grammar.
Seville is probably the most beautiful city I have been to and my favourite place there is the magnificent Plaza de España in the Parque María Luisa, built for the 1929 Ibero-American Exposition. Its one of those places you have to visit to appreciate fully, but I hope that the photographs below give you some impression of it.
Of course the city has many other beautiful sights...
...but I was there mainly to learn. The teaching was excellent and there was also a large number of cultural activities and visits to make. The teachers were all very enthusiatic and there was an excellent range of nationalities in the class, which ensured that Spanish had to be used as the lingua franca.
We did have fun as well, though, with many fiestas in true Andalucian style!