If your trip to Barcelona is all booked but your travel itinerary is looking a little empty, we can give you a helping hand.A look at a postcard stand will tell you that a trip to Barcelona wouldn't be complete without going to Sagrada Familia. As the most famous sight in the city, you might want to spend more time here than a quick stop.You'll need to rise with the sun if you're planning to check out all the great attractions this place has to offer. Gran Teatre del Liceu and La Rambla are non-negotiable. Barcelona Cathedral and Placa de Catalunya shouldn't be forgotten either.Plan a stop at Barceloneta Beach. It's one attraction you'll usually find on many travelers' to-do lists. If you still have space on your itinerary, Barcelona Aquarium and Picasso Museum will keep you busy as well.