Barcelona is a city with something for everyone, including those who don't want to spend a lot in order to have a great time. If you feel like exploring Barcelona 'on a shoestring,' then here are some great ideas.
As far as transportation goes, although taxis aren't that expensive, the cheapest way to get around is to use the metro (subway) or the bus. Buy a T-10 pass from the metro station for 11 Euros. This gives you 10 trips via metro or bus at any time within 30 days of your stay in Barcelona. The card is also transferable between people; if there are two of you, that's 5 rides each which is usually more than enough for one day in the city.
Once you've bought the pass, hop on the green line and go to Lesseps stop. This is where you'll find the magnificent Alice In Wonderland-esque park of Antoni Gaudi. It doesn't cost a cent to get in and if it's a nice day outside, you can spend hours walking around admiring the innovative and unique designs by one of Barcelona's most famous architects. Park Guell provides for spectacular city views and also features the longest bench in the world.
Park Guell — Photo courtesy of Park Guell
After the park, you can either go for a leisurely, long stroll (approx 45 minutes) to Gracia neighborhood or you can take the metro to Diagonal or Fontana stop and go for a short stroll and some tapas.
Gracia used to be a city unto itself and today is one of the most authentically Catalan areas in Barcelona. It's not a particularly touristy neighborhood, thus food, drinks and clothes are slightly cheaper than in the Old City. If you're looking for tasty and affordable tapas on an outdoor patio, go to Sol De Nit which is in Plaza Del Sol. Salads run about 5 Euros, as do most of their other options. This is one of the best places to people watch, catch some sun and enjoy a leisurely lunch in a cool, hip and local neighborhood.
If museums and/or cathedrals are more your thing, then head to the Picasso Museum in the Born. Tickets are only 11 Euros and this is a definite must-see if you're into art, or just curios about the life of the famous artist. As for cathedrals, the Santa Maria Del Pi is a smaller church in the Gotico, beautifully constructed at the beginning of the 14th century and doesn't cost anything to enter. The Cathedral La Seu is a much larger one in the Gothic Quarter, free to enter and utterly breathtaking.
And if you want to take a stroll on the boardwalk before dinner, grab the yellow line to Barceloneta stop or walk from the Born or Gothic Quarter (15-20 minutes) and you can enjoy the Mediterranean coast without spending a dime. If you're in the mood to 'splurge,' grab a coffee or a drink at the W Hotel and enjoy the views from their terrace.