Europe is blessed with seamless interconnectivity through its road and rail networks. For example, one way of visiting Ireland is flying into Belfast and then driving from Belfast to Dublin (90mins). Same can be done from Amsterdam to Paris or by train from London to Paris (2hrs 15mins) or Berlin to Prague (4hrs 15mins). And then there are of course flights that can get you there much quicker but that is after having to deal with getting to the airport and through airport security.