Koblenz is located within one hour travelling time of three major German airports:
Frankfurt, which is a main European hub and home of Lufthansa (rates will be comparably expensive),
Frankfurt-Hahn, which is a hub of the low-cost airline Ryanair and
Cologne, which is served by major airlines and low-cost carriers as HLX, Germanwings, EasyJet.
Koblenz can easily be reached by train, for example from the Frankfurt/Mainz area, Cologne area or Trier. At the train station is the bus central station. From there you can reach most areas of town (bus lines run mostly from 5:30 to 23:00).
Three German motorways lead to Koblenz: A3, A48 and A61.
Many bus companies offer trips to Koblenz for one day ore more days.
Deutsches Eck. This spot (the name means German Corner in German) is where the Mosel River meets the Rhein River. The tip of the park is shaped like a ship's prow, overlooked by an enormous equestrian statue of Kaiser Wilhelm mounted on an equally-huge stone base that you can climb for a great view of the rivers and opposite shore castle.
Watch Soccer at the Oberwerth-Stadium and see TuS Koblenz 
Koblenz has a big shopping center (Löhr-Center) with some 130 shops, located in the city centre.
Excellent regional Wine and Food you'll find at Wirtshaus Alt Coblenz.
The ****-Rhein-Hotel Diehl's Terrassen is situated directly at the Rhine, below the Ehrenbreitstein castle, with a view of the Deutsches Eck from every room. Unfortunately, only a few metres from a busy railway. (Diehl's hotel)