Let's face it, Barcelona is not Paris or Rome in terms of monuments. But what makes Barcelona the city everybody wants to be in, is the vibe.
The city has a vibrant nightlife, a relaxed mood, and breathes creativity in every corner.

So, no matter if you only have one day, the best way of experiencing the city is walking by is main neighborhoods while doing sightseeing.

1. Start your journey at stopping in Fontana's metro station (Green line). This is the heart of Gracia, a hip neighborhood where you can still find little food shops, squares full of people enjoying a coffee in their terraces and many many young people.
Perpendicular to Gran de Gracia on the left you will find Carolinas street where you can find the hidden secret of Gaudí. You will easily find Casa Vicens one of the first houses built by Gaudi on the city and still inhabited by a family. It's not a very touristic one so tours are not scheduled.

2. Once you have seen it, you can keep going down Gran de Gracia straight until you see Diagonal. This should take you around 15 minutes and you can see some of the Modernist arquitechture built during the XIX century. Diagonal is the main Avenue in Barcelona that cuts the city in half.

3. After crossing Diagonal you will see the beginning of Barcelona's Golden mile; our very own 5th Avenue or Champs Elysee. Here you can find most of the top brands (such as Gucci, Channel, Armani) and as well others such as Zara or H&M.
But, above all, what makes this street a symbol of the city, is its combination with Arquitechture. Here you will find two of the main Gaudi's buildings as well as some other modernist beauties.

4. First compulsory stop on the street is Casa Milà, commonly known as la Pedrera. The story says that the Mila's family ordered the house but however never actually lived in it since everybody in the city commented that looked a big rock. Today it has become an emblem of the city and a point of reference to any Architecture or Art student. There are organized tours to one of the apartments and to the roof. You may as well visit an art foundation that lays on the building's 1st floor.
Specially interesting is the roof and the chimeneys, these look like a giant army controlling the city. The purpose of such shape was for the laundry not to be seen from the street!

5. Couple of blocks down the street, right on the intersection of Arago and Passeig de Gracia you will find the most interesting block in Barcelona, also called Apple of Discord. This term is in reference to the fact that 3 houses were built by some of the most important modernist architects: Casa Amatller (designed by Puig i Cadafalch), Casa Lléo Morera (designed by Domènech i Montaner) and Gaudí's Casa Batlló.
ll three houses were designed in a different interpretation of the modernist style in what seems like a competition between the architects. This lead to the local term 'Mançana de la Discordia', which means apple of discord, referring to Greek mythology where an apple, given by the goddess Eris 'to the fairest' lead to a dispute between three goddesses, eventually leading to the Trojan War. Conveniently the word mançana also means 'block', so the expression 'Mançana de la Discordia' can also be translated as 'Block of Discord'.

6. At the end of Passeig de Gracia you will find Plaza Cataluña, the epicentrum of Barcelona. Here you can connect to any part of the city by underground or bus since it is very well communicated. You have as well two main shopping atractions for all locals: El triangle (little shopping mall with FNAC inside) and "El Corte Inglés". If you walk to the very center of the square you will find as well many tourists feeding the pidgeons, up to you doing it! But keep in mind thought that a local would never do it ;)

7. From that point on you have 2 choices: either go right and take "Portal de l'Angel" or go left and take "Las Ramblas". First choice is a purely shopping boulevard that ends in the cathedral main square, while Las Ramblas will lead you through the colorful chaos Barcelona represents for many people. Both of them are 1 minute from each other so you certainly can move from one to the other. In this area of city since it is always crowded be aware of pickpockets!