Questions related to airports themselves rather than "airlines" and "air-travel", which have their own tags. "Airport-transfer" is also covered by a separate tag.
Questions related to airports themselves.
Note that questions can be tagged for individual airports using the standard 3-letter airport codes such as lhr for London Heathrow.
Photius Coutsoukis has a listing of IATA codes at http://www.photius.com/wfb2001/airport_codes_alpha.html#G with useful search facilities.