You can take a selfie in front of the hilltop Schloss Heidelberg and look down at the old town, or stand on the arched, stone-brick Alte Brücke across the Neckar River and look up at the famous castle ruin. Or, hey, catch that funicular, the Heidelberger Bergbahnen, up the mountain for a kickass view of it all. And in town, you can join the uni students at the student pubs for a few craft brews led by "Vetter 33" – that's a whopping 33% alcohol content! – the strongest beer on the planet.