Frankfurt am Main International Airport - FRA (28km).
By public transport:
From Wiesbaden Main Station take bus line 262 towards Hofheim am Taunus Bahnhof, or bus line 46 towards Hochheim (Main) Berliner Platz, to the station Siegfriedring. When you get out there, you'll see a pedestrian bridge, which you have to pass over. You'll see pentahotel on the left side.