Here are some areas you cannot miss:
Gothic Quarter Barceloneta Beach Parc Citudella Montjuic (for views of the city & Magic Fountains at night) La Rambla Tibidabo Tip: the "Bus Turistic" hop on/hop off bus is a great way to see the city in a day!
We recommend purchasing tickets in advance!
Sagrada Família Park Güell Casa Batlló Casa Milà (La Pedrera)
So many places to grab a bite. Here are a few we love:
La Boqueria market (Try El Quims!) Bar Canete Bodega de la Puntual Viana Granja Dulcinea (for churros!)
For adventures outside Barcelona and Tarragona:
Montserrat Sitges Costa Brava Girona