LTN is very close to the town (LTN obv, not London).

Luton Borough Council don't have a residents parking scheme in the area very close to where you can get a free bus from the terminal.

Please don't change this ;)

Hmm, nor does Solihull MBC in Hampton in Arden (3 mins on train), don't think they do around Marston Green either. Plenty of parking shuttle buses milling around there, but not sure if security would just let you walk in, probably not!

Concession pass holders wouldn't pay for the train anyway.

Would say Nice Côte d'Azur Airport (NCE) qualify to be called a city airport - with one single road with walkways, Promenade des Anglais, leading you the whole way from the city centre to the airport. It will be tough 3.6 mile long walk, but then you can enjoy the view of Mediterranean until you reach the end of the runways.

DXB, could not get more 'in town'!

And can still enjoy once inside the departure lounge :)

RKV, Reykjavik Domestic (which has flights to Greenland, so is international) is easy walking distance from the city centre, took me about 20 minutes. KEF, on the other hand...bit further away.

Biarritz (BIQ) is at walking distance (35 mns) from the city center and the "Grand Plage". The airport is actually closer to the city center than the railway station !

Now if we were to do airports which are closer to town than the railway station, then there might be a few of those - assuming the town has a railway station.

I'll start with SKB - it might only be a sugar train, but the "terminus" is adjacent to the RBIA terminal, both being about 40 mins from Basseterre.

2 more:

1. SDU
2. TSA

Ostend-Bruges International airport is a 40 minute walk from the centre of Ostend, and less than 10 minutes walk from the beach ;)

San Diego Airport is not too far from Downtown.

Ponta Delgada in the Azores, 2km/1.25 miles

And yes, it is a town (the largest in the islands). And the airport has intercontinental scheduled flights.

Arrecife airport - Is not that far from the city, and not that far from Matagorda, about 3 miles.

BLK is an international airport, so it counts and is say walking distance from the South Pier.

Kai Tak was in town (if not the business centre) and both Luanda & Lisbon are damn close in

The old Jakarta domestic airport at Kemayoran was also surrounded by houses. and Adelaide is right in the city if not the absolute centre

Copenhagen and Lisbon are nice and close, although with a train station underneath the Arrivals hall at Copenhagen, I dont know why you would want to walk it!
Las Vegas has already been mentioned, as has San Diego, but I reckon Innsbruck is one of the closest... a brisk 30 minute walk.

Bucharest Baneasa is pretty close to town.

SDU (Santos Dumont, downtown Rio) has been mentioned. (I don't think airports come much closer to the centre than that), and there's Congonhas which is definitely downtown in Sao Paulo, although it's a sprawling city. Moscow had a city airport - actually called Centralni - until about 2005, (opposite the Lenin Stadium on Leningradsky Prospect for those who know Moscow), but it's now closed and has been built upon.

I've walked from Lisbon to the airport, quite a pleasant walk. I would not want to do that between Bucharest and Baneasa, it's further and walking along that road would not be fun. Henri Coanda (Otopeni) is only a mile or two further out than Baneasa.

I've walked from one of the huge nightclubs adjacent to AEP back to the apartment where I was staying in Recoleta, on the north side of central Buenos Aires. Was completely ****ed but guess it took about half an hour.

Antwerpen Airport