6 hr layover in Barcelona, what to do?

Hi Janet,
In fact 9:30 to 4 might seem a long time but actually it's not that long if you move about. I would probably take the Aerobus to Plaça Espanya (the main entrance to the city from the west, and the closest to the airport too) which should take you 20-25" and visit the area, you have several art and architecture museums there, or if you're not in the mood, you can simply stroll the many parks in Montjuïc, a bit further up the hill (you have one of the few gardens specialized in cactus in Europe for example) or something more mundane: go shopping at the little shops along Carrer de Sants (for info, carrer is Catalan for street) or at the Les Arenes Shopping Centre (in Plaça Espanya itself), which also has some tapas places at ground level and some restaurants at the top.
In case you're interested, there's a permanent taxi rank at Plaça Espanya. A taxi to/from the airport should cost you around 15-20€ (which includes the supplement, 4.20€ I believe, to get in/out of the airport). In fact you might want to take taxi both ways as the Aerobus above mentioned will cost you 5.90€ p.person each way.
Enjoy!

PS. Have you checked how much is a low cost flight from San Sebastian direct to Madrid?? it might be more efficient to get another ticket (if you find a low fare) and avoid having to spend only 6 hours in Barcelona plus the flight time from SS and to Madrid... try www.vueling.com and ryanair.com

You will pass a large IKEA store between Barcelona's airport and the centre.
Do you think you could find your way back out within six hours?

Just kidding, I like the Montjuic suggestion ...
Placa d’Espanya - Les Arenes - Palau Nacional - Caixa Forum - Mies van der Rohe Pavilion - MNAC museum - Anella Olimpica - Miro Museum (Fundacio Miro) - Montjuic Fort

hahaha!, I subscribe that @djp_syd... I suppose you mean that habit of our dear Swedish friends of forcing you to follow a pre-set route to get out of their shops, huh? :))) Actually, a few years ago in the one in l'Hospitalet (the one you mention) they "had" to open a few shortcuts for those willing to go straight to the end of the shop because people were making their way through anyway moving stuff to go pass.

Another althernative to consider: an airport lounge. Depending on which credit card you have, you could have access to a very discounted rate. All lounges will have free food, internet, very comfortable seating,- some even have showers and other amenities.

We had a 4 1/2 hour layover in Madrid and it worked out great.

Thank you gentlemen, I appreciate your suggestions (and humor). I'd love to change our ticket but it was not flexible. Careless mistake on my part not to notice the layover. But I'm sure more time in Barcelona won't be too tough to take.

Janet

What I would probably do, in all seriousness now, is get a bus to Sitges and have a look around, especially if it's a nice sunny day.
Mon-bus leaves T1 Barcelona Airport hourly for a 35min ride to Sitges. http://www.monbus.cat/en/
Sitges is a lovely seaside town, with a nice promenade, wide beach and charming old centre.

For the contrary view -- Five, six hour layovers are suckers play. You think you should have enough time but your really don't. Just run some time lines and see how much time your really have. You have to back at the airport at least an hour before and I would push for an hour and half or maybe two just so you can get through security again. Your transportation to and from above recommendations with chew up another hour and doesn't include any wait time for buses - maybe another 30 mins or more. Then there is just getting off the plane and hike to the bus stop - 15 - 30 minutes. You can soak up a good four hours of your six half so maybe leaving you at most two hours, maybe three. There are some nice duty free shopping in Madrid and couple bars. You may want to just wait it out.