Barcelona Drive - So much to see, so little time! 
If that's what you think, you won't believe how much can be achieved in only 4h when you are in the hands of an experienced licensed tour guide and a professional driver. 

My favorite itinerary covers the 4 main sightseeing areas in Barcelona: the Gothic Quarter and the Cathedral area in the Old Town, some of the best Gaudí sites (Casa Batllo, Casa Milà / Pedrera and Sagrada Familia Church), the Montjuic Hill (1929 World fair, 1992 Olympics and city views), as well as the waterfront (Old Port, Barceloneta fishermen district, beaches and Olympic Village marina).
There will be frequent stops to get pictures and learn more about the sites, but in this itinerary there isn't time to go inside them. If you are interested in doing it, we'll be glad to adapt the tour in order to fit your preferences.

Barcelona in a walk - Barcelona is a quite walkable city, and in the center there are great sites just a few blocks from each other. There isn't a more authentic way to discover it!
My favorite 100% walking itinerary would be starting in the Old Town and covering the Gothic Quarter and Cathedral, Jewish Section, Rambla and Boqueria Market, then entering the Eixample district, built after the city knocked down its walls and started expanding across the fields around it. Here florished the Modernist style (local Art Nouveau), and the architect Antoni Gaudí created imposant and excentric buildings. We'll walk along the elegant Passeig de Gracia main street to see his Casa Batllo in the Block of Disagreement and the Casa Milà or Pedrera a few blocks further. At this point, you can choose to enter one of these impressive houses, or either continue to the unbelievable (yet still unfinished) Sagrada Familia church, his masterpiece. This last option involves 20min walk or 5min subway or 5min taxi ride. 

Barcelona for foodies - Our city is a gourmet paradise! Let's get a taste of it together!
In this walking tour we'll start visiting the amazing Boqueria Food Market, oldest in Barcelona and largest in Spain. There we'll see lots of local products, along with exotic ones that you might never have seen before. Fruits, vegetables, mushrooms, fresh fish and seafood, meat, sausages, cheese and much more!
After this we'll continue strolling around the Old Town stopping in a dozen different food stores of all kinds. Some of them have been recently open, some others have been around for over a century, but all of them are great!
The last hour of the tour we'll stop in a couple of authentic tapas bars so you can try different local specialties and learn more about the Catalan and Spanish cooking. Or alternatively, we can keep strolling to discover some other gourmet stores or do some sightseeing.