Like any other big city in the world, Barcelona does have a subway system. But, unlike many cities, the Barcelona metro is pretty safe and reliable - you can even use the metro for going out in the night.
Of course it is important to stay alert for pickpockets and so on. But, as there is no violence, you can safely cross the city underground. My advice is to buy a weekly pass that allows unlimited journeys during this period.
The Metro system runs all over the city and is again quite easy enough to follow with the maps being self explanatory. You can purchase multi-day tickets and save a fair bit of money over what you would pay on singular journeys. The trains were new, clean and comfortable for short journeys. Avoid travel in the usual rush hours if you want a seat.
One of the things to bear in mind with the metros are that some of the lines are only operated by funiculars. They usually only operate in summer months and are attached to some lines that lead directly to certain tourist spots (Castell de Montjuic, Tibidabo to name a few). Also the metro stations are fairly clean though have their fair share of starving musicians and most of the tunnels are open canvasses for works of poetry or prose. Bear in mind also that many of the stations have multiple entrances/exits. So it may help to check a map once you get off the metro to get your bearings. There are always voices to tell you which station is next as well. There are also a lot of stairs to climb with very few lifts or escalators.
The metro in Barcelona is really easy to use and pretty affordable. There are five different lines as well as train access to cities outside Barcelona. The main lines are identifiied by color as well as number so don't be confused to find out that the blue line is also number 5. Yellow-4, Green-3, purple-2, 1-red. A 10 ticket is a good option because it can be shared and costs about 6.50 euro. This 10 pack (one card which can be used 10 times) will also work on city buses, so you have the option of using both. With so many places close together you should be able to get through a short trip to Barcelona by walking to many places and only purchasing a couple 10 trip cards.
The Barcelona Metro is clean and efficient. Most places of interest can easily be reached by the Metro.
Metro operates from 5am to midnight (Monday to Thursday and Sundays), and 5am to 2am Saturdays and Sundays.
The metro system in Barcelona is great and easy to use. On every stop there are maps of the whole system and it's very easy to navigate and find your way around. We used the T-10 ticket which allowed us to switch trains in one ride- every ride is good for 1h and 15 min.
The trains are fast and we didn't wait more than 4-5 minutes for a train. At the entrance of every stop there are machines to by a ticket in several languages- fast and easy, and maps of the stops of each train.
The metro in Barcelona is not as good as the one in Madrid. Although it always runs on time (stations show you the exact time left for the train to arrive), the frequency of the trains is not very high, plus the stations are not scattered everywhere in the city as you wish they were. But, it is a very good option if you need to get from A to B quicky.
The Metro of Barcelona is operated by TMB (Transports Metropolitans de Barcelona). The 5 lines serve 111 stations. A single metro ticket costs 1,05 EURO, while 10 tickets for Metro and bus (T-10) cost 5,80 EURO (2003). Moreover travelpasses for 1 to 5 days are available.
In general we would suggest to tourists when touring Barcelona, use the metro if your destination is too far to walk. Although many and most of the tour sights are within walking distances from each other but some are a bit further away and most of them can be easily and effeciently reached by metro. So far, there are six different lines, each with a different colour and number for easier to remember and recognize. The metro here in Barcelona is in full swing from 5 in the morning till midnight on Sundays, Mondays, Tuesdays, Wednesday and Thursdays. On Fridays and Saturdays which is considered a weekend it is in full function from 5 in the morning till 2 in the morning. Even with us locals we purchase the T-10 card which is good or valid for ten rides (those that labels zone one and so forth, I find it only confusing as we use these for all rides and is legal and acceptable by the metro machine., the metro, busses, FGC trains and rodalies are also accepting the metro tickets for transfers. You are allowed to change between the different transports and each ride is valid for one hour and 15 minutes. You can buy the cards in machines at the metro entrances, using cash or even bankcards. A T-10 CARD is 7.20 Euros (effective 02/08) For single ticket riders is quite expensive they cost 1.30 euros single ride. Now if your going to use the city airport bus, it cost 2.10 by bus, which you can pick up right in front of El Corte Ingles. If your going to Girona from Barcelona (by regional train) 5.90 Euros from Mondays through Fridays.
Barcelona has an excellent metro system whose five lines reach nearly every interesting sight in the city. At each station the directions of the trains are clearly signposted. Trains run from 5:00 to 24.00 during the week and until 02:00 at weekends and holidays, though there are plans to extend the timetable. The last metro is signalled by a hooter as it comes in. Get a multi trip ticket (tarjeta multi-viaje Y-10) which allows you 10 journeys and is much cheaper than buying single tickets.
The metro is great in Barcelona. If you are staying for a week or more (even just a couple of days) you can get a metro pass for like six or something rides for 6 euros or something like that. Basically, check out the ticket machines and get a bulk pass for metro trips if you are going to be around. You will save a lot of money.
The T-10 is a transport ticket with 10 rides and is good for the metro and bus and several people can use it. Every ride is good for 1h 15 min (for zone 1- almost all the main atractions are within that zone) which means that for example you can use the metro and the bus in one ride. For 7 days in Barcelona we bought 2 T-10 tickets, every ticket costs 7.95 euro.
We found the metro system in Barcelona very useful, and our three day travelcard good value for money when using it, especially as our hotel was at a little distance from the town centre and some of the places we wanted to visit were rather spread out too. The maps were simple to use to work to the best route and the clear signs at each station made it easy for us to find our way from platform to platform, when we had to change trains. It was a quick efficient way to get from place to place and we never seemed to have to wait long for a train. We also felt very safe using it, even late at night.
Of course the disadvantage of travelling along underground is missing the view of this beautiful city that you would have travelling above ground and we also found that, as with the London underground stations, we often had quite a long walk, sometimes with stairs, when changing trains. We didn't mind this for our sightseeing but found it more difficult with our entire luggage when travelling from the airport to the hotel, so on the way back, we decided to take a taxi instead, which was well worth the extra cost.
There is a clear printable map available on the website listed, which shows the metro and other connecting public transport services.
Barcelona has a very good metro system, which can take you almost everywhere. Unfortunately not to Parc Güell. The metros do show up a bit late a lot of times. This doesn't matter too much, because the metro's run very frequently. Try to avoid the metro station of Passeig de Gràcia if changing metro's because you might end up walking the marathon, since the distance from one line to another is too big!!
You can use this ticket from the airport and can be used by more than one person. We bought 2 of these tickets during our stay and used them for 2 trips to and from the airport, return to the Nou Camp and return to Parc Guell. This cost us €6.90 each and it costs that to go just to the airport so we got 8 free trips.