Overnight layover in Frankfurt

Hey, I may have a layover of roughly 2 days in Frankfurt and am looking for anyone locally/regionally for some advice. I'm interested mainly in some good local restaurants and "must-sees" (mainly historical places). If there is a recommended B&B not too far away, that would be nice too. Because it's such a short time, I'm trying to squeeze as much in as possible. I'm a fairly adventurous traveller, so I'm up for (almost) anything. You can PM me if you want. Thanks Intercotees