My sister and I looked on all of the airlines, and we determined our first city by the cost of the flight. We flew into (Aer Lingus)Shannon, Ireland first. Ryan AIR has awesome flights all over Europe, and I highly recommend flying on Ryan Air across Europe instead of using the trains. Most of our tickets were around 14 Euros!! It’s quicker and easier! We flew from Shannon to London to Berlin… and then took the train all over Europe. We didn’t know how much cheaper it would have been or how much easier it would have been by purchasing airline tickets.