Frankfurt is a major communications and transport centre, and consequently gives many travellers their first taste of the country. It's a place with a surprising amount to offer and it's worth spending at least a couple of days here rather than treating it as a mere transit point.
Over half of the city, including almost all of the centre, was destroyed during World War II and the rebuilders decided to follow a policy of innovation rather than restoration. The result is a skyline that smacks more of New York than the Federal Republic - appropriate enough in a city that has the reputation of being one of the most Americanized in Europe and whose most commonly used nickname is Mainhatten.
It's also a surprisingly civilized metropolis which spends more per year on the arts than any other city in Europe, and whose inhabitants like nothing better than to spend an evening knocking back a few jugs of the local apple wine in the open-air taverns of the Sachsenhausen suburb.
Frankfurt has an energetic nightlife and is a thriving recreational centre for the whole of Hesse, with a good selection of theatres and galleries, and an even better range of museums, mostly concentrated along the south bank of the River Main. It comes across as a confident and tolerant city, and in the Bockenheim district there's a healthy "alternative" scene, not self-consciously institutionalized in the way that Berlin's has become.