You could head down to Dragør (bonus points if you can pronounce it ) While it's a rather long walk (1h25 Google Maps reckons) along the coast road around the aircraft perimeter, there are also bus services to/from the airport. It's a bike ride I used to always enjoy doing (even if the wind makes it rather difficult at times). It's a pretty little seaside town, surprisingly quiet given it's enveloped by the airport.