Jogging -- A pretty jogging route is along the quays of the River Main, using both sides of the river and the bridges to create a loop. Another choice is the centrally located Gruenberg Park, with walkways that are suitable for jogging. Tennis -- Few of the tennis courts in Frankfurt allow nonmembers to play. A noteworthy exception is the Tennisplatz Eissporthalle, Am Bornheimer hang, 60486 Frankfurt (tel. 069/21230825 or 069/212393081), which has a half-dozen courts. They're open May to October daily 8am to sundown. The cost is 10€ ($13) per hour. | 
