Barcelona is a fairly massive metropolis. You'll be able to walk to many of the principal attractions. But, in the event you’re in Barcelona for 3 times, you’ll finally end up looking for transportation. Go ahead and take metro or taxis. The Museu Marítim shows the navigation on the Mediterranean https://www.triptales.me/unlock-barcelonas-hidden-treasures-secret-spots-you-cant-miss/