1. Frankfurt Airport (IATA: FRA) is found 12 kilometres from the city centre of Frankfurt and is Germany's biggest and most important airport. It receives flights from almost all national and countless international destinations, including intercontinental flights to Asia, Africa, North America and the Middle East. It's the biggest airport in the world regarding the number of international destinations served. Among others, Frankfurt is the primary hub of German national carrier Lufthansa.

To/from the airport:
Frankfurt Airport has a long-distance train station serviced by ICE to various destinations, and a local train station with plenty transport opportunities in the region and to downtown Frankfurt:

Frankfurt Airport Regional station at Terminal 1 provides access to the S-Bahn commuter rail lines S8 and S9 which depart every 15 minutes during the day to Wiesbaden in the west via Rüsselsheim and Mainz and to Hanau in the east via Frankfurt Central Station, Frankfurt city centre and Offenbach am Main. The journey time to Frankfurt Central Station is 11 minutes, to the city centre (Hauptwache) 15 minutes. Services roughly run from 4 or 5am to around midnight or 1am. Regional-Express trains to other destinations like Saarbrücken in the west, Koblenz down the Rhine valley to the north, or Würzburg in the east also call at the Regional Railway Station, as do some long distance trains, especially at night when the Long Distance Railway Station is closed.
Frankfurt Airport long-distance station was opened in 1999. It is the end point of the newly-built Cologne-Frankfurt high-speed rail line, which links southern Germany to the Rhein-Ruhr metropolitan area, the Netherlands and Belgium via Cologne. All ICE trains between Cologne and southern Germany stop at Frankfurt Airport, taking slightly less than an hour from Cologne. About 10 trains per hour depart in all directions.

Of course it is also possible to rent a car to explore the world-renowned German Autobahnen. Frankfurt Airport is directly connected to a Autobahn intersection called Frankfurter Kreuz where the A3 and A5 meet. It takes a 10-15- minute ride by car or taxi to get to Frankfurt Central Station or the city centre.

2. Although located 120 kilometres from Frankfurt, the Frankfurt-Hahn Airport (HHN) can be of some significance if you want to have more choices regarding lowcostairlines. Ryanair is the main operator with flights to/from Alghero, Alicante, Bari, Berlin, Birmingham, Bologna, Bratislava, Cagliari, Carcassonne, Dublin, Edinburgh, Faro, Féz, Gdańsk, Girona, Glasgow, Gothenburg, Jerez de la Frontera, Kaunas, Kerry, Klagenfurt, Lanzarote, Las Palmas de Gran Canaria, London, Lübeck, Madrid, Málaga, Manchester, Marrakech, Milan, Montpellier, Osijek, Oslo, Palma de Mallorca, Pescara, Pisa, Porto, Prague, Barcelona-Reus, Riga, Rimini, Rome, Santander, Santiago de Compostela, Seville, Stockholm, Tampere, Tenerife, Trapani, Valencia, Venice, Wroclaw and Zadar.

To/from the airport:

Bus: The airport is served by a number of (mostly) private bus operators that run regular services to Frankfurt am Main (1 hour 45 minutes, via Frankfurt International Airport - Terminal 2), Cologne (2 hour 15 minutes), Luxembourg (1 hour 45 minutes) and a number of other cities in western Germany and the region. Frequent buses also run to the main railway station of nearby cities, the closest being Mainz (1 hour 10 minutes) and Koblenz (1 hour 5 minutes).
Rail: The airport has no railway station and the nearest railway stations are Bullay (15 kilometres) on the Koblenz-Trier-Saarbrücken line, and Idar-Oberstein (26 kilometres), Kirn (22 kilometres) and Bad Sobernheim (30 kilometres), all on the Mainz-Bad Kreuznach-Saarbrücken line.
Car: The airport can be reached by road, the nearest Autobahn (Highway) connections are approximately 40 kilometres to the west (A1) or east (A61). Parking(short-term and long-term) and car rental facilities are available at the airport.