Agreeing with Lorsin
lots to see & do within walking distance. If you are interested in Gaudi, then apart from the Sagrada Familiar, there are the apartments (La Pedrera and the Casa Battlo) which are worth seeing, both outside and in, there is the Park Guell which is a wonderful park full of bizarre architecture.
There is the footbsall stadium & museum, if you are into sport. It is quite amazing and better than many national stadiums around the world.
The watefront is a great place to spend the evneing if the weather is kind to you.
I am sure whatever you plan to do, you will have a great time,
Enjoy & happy voyages,
Alan & Katrina
Last Cruise: Queen Victoria November 2014
Next: P&O Britannia March 2015
Then: Minerva April 2015
and : Royal Princess August 2015
Golden, Grand(2), Caribbean, Sea(4+1 aborted)
Adonia(4+2), Arcadia, Artemis(2), Aurora(5), Azura(2), Oceana(3), Oriana(11), Ventura(2), Victoria(5)
QM2(2), QE2(9), QV(6), QE, Caronia(2), Minerva II, Fred.Olsen(8), NCL Jade, =X= Eclipse, HAL Ryndam, Aza.Journey