Germany 
in $530s-$570s RT
OliviaJFC
We found a neat little prem eco route to Frankfurt last week, when we told you about all the European destinations within an afternoon's train ride of this German hub. Frankfurt's central location and stellar rail connections make it an all-purpose starting point for pretty much any Central European vacation.
Buuuuuut before you hit the tracks, maybe spend a day in the city? The Museumsufer has a whopping 39 museums along the River Main, ranging from major art institutions to local history collections to German arthouse theatres. For €21, you can visit as many as you like, so why not camp out here for a couple days and recover from jet lag with Rembrandt and Holbein?
Jack's take
We love a good non-stop to Europe (especially one that lands you in such a well-connected spot!) and this one dropped by $50 RT.