Transportation in Barcelona. Hands down one of the easiest and most accessible systems I have ever experienced. Apart from busses, all Public Transportation is underground: trams, trains, metro, etc. With schedules that run on time and late into the night and routes that run to the edge of the city, you can get anywhere with the swipe of one card. One could even argue it is the most used form of transportation here, with cars, taxis, bicycles, and mopeds leading behind. The city even has designated bus/taxi and bicycle lanes. The system is so advanced, I have yet to see any traffic!
The availability of access to the city by means of the transportation that best suits you is astounding. The simplicity of the system creates an inviting atmosphere as well as one that encourages adventure and community. No wonder everyone is always out and about!