Tibidabo. Located on the mountains of Barcelona (farther north from Gracia) and offers a spectacular view of the city (532 m high). This is a place where according some legends, the Devil tempted Jesus Christ offering him the whole world in exchange for his worship. At the top there is an awesome church, which offers panoramic views of the city. The church is almost completely surrounded by a big funfair. You will also find an observatory and an ascendable communications tower nearby. To get there, take the metro (L7) to Av. Tibidabo Station, then the "Tramvia Blau", and then the Funicular up to the mountain. It takes a good hour or more from Sants, and a little longer from the center. A much cheaper (and still fast) way is to take S1/S2 suburban train to Peu del Funicular, then ride up to Vallvidrera Superior by a cablecar, and then take bus No 111. The beautifully scenic walk down is lined with some un-missable Spanish architecture for your photo album. You can not take photos very well from the tram, but the walk is wonderful. The cafe con leche at the cafe near the church is terrible. Try at the bottom of the funicular.
Monestir de Pedralbes, Baixada del Monestir, 9. A beautiful Gothic monastery near the university, there are a picture gallery (the Thyssen Bornemisza Collection), a museum which depicts the monastery life, a church, and a marvelous chapel covered with medieval frescoes.
Museu de Ceramica (Ceramic Museum), Avenida Diagonal 686. At the Gaudi Pedralbes Palace, 
CosmoCaixa, . Isaac Newton 26; 932 126 050. The city's science museum and probably one of the best places to visit in Barcelona. One of the best science museums in Europe. Located near Avinguda del Tibidabo.
Hospital de la Santa Creu i Sant Pau. Stroll around the beautiful grounds of this hospital. Check out the tiles in the convalescent home, and see if you can sight any of the stray cats. Due to construction in some of the wards, you will enter the grounds of the old hospital either through the beautiful chapel or the garden near the new hospital.edit
Parc del Laberint d'Horta. Try out the labyrinth in the center of this park. The park also has a nice waterfall, a romantic canal and gardens. A quiet place to relax for several hours away from the busy city. Free of charge on Wednesdays and Sundays.€2.07. edit
Hisop, passage Marimon 20, . One of the most promising cuisines in Barcelona with excellent wine service. Mains around €20.
Can Punyetes, C/Maria Cubi 189. A very traditional Catalan restaurant favored by locals. Menu in Catalan, but it's worth the risk, the food is delicious.edit
Origen 99.9%, Muntaner, 409, ☎ +34 932-014-579 (email@example.com), . 12:30PM-1AM Mon-Sun ('''no break for siesta'''). Eco-friendly chain of Catalonian-cuisine restaurants; organic only in some of products. Good choice of specialty liquors.main courses: fish €5.5-6; meat: 5.85. edit
Udon, Centre L'Illa Diagonal, Avinguda Diagonal, 545-565 (Metro Maria Cristina (line 3)), ☎ 93 444 11 99, . Mon-Sat 13-21:15. A chain of inexpensive noodle restaurants inspired by a japanese chain Udon Ya, serving tasty Japanese cuisine. No reservations.edit
Sutton - Located on Diagonal, this club hosts Studio 54 on Thursdays. If you like House or Techno music this is a must. Open until the metro starts back up, Sutton has a very large dance floor with two VIP rooms. It also has a small stage where multiple go-go dancers perform throughout the night.