"Sex tourists not welcome here," shouts a plaque outside the main doors. "Zero tolerance of trouble makers and all illegal activities," yells another.
Also forbidden at this "sleaze-free zone" are "junkies, louts and other degenerates", feet or luggage on the tables in the foyer, noise by the pool after a certain time "or you won't get any breakfast" and swimming togs in the restaurant.
And don't even think about attempting to bring in bargirls or catamites (look it up) because you'll be told "in plain language" to settle your bill and leave.
But don't assume all these rules add up to no fun at this hotel, which was founded in 1954 as the premises of the Atlanta Chemical Company by German chemical engineer Dr Max Henn.
Though it looks like a dull, low-rise concrete block from the outside, the minute you step through its front doors you're transported back in time. The Atlanta has been preserved in all its former glory.
The foyer, cool and dark, has retained its 1950s style complete with Art Deco features, including a writing room and library, old telephones, terrazzo floor and two magnificent bronze dachshunds.
Its crowning glory is its outdoor swimming pool built in 1954, the first hotel swimming pool in Thailand and the largest pool in the country for more than a decade. After a day - or even an hour - in the city's sweltering heat and humidity, this pool is literally an oasis. There are comfy hammocks along one side, Art Deco dining tables, chairs and loungers, as well as music "poolside" from 6pm, a dated gym, and a lush garden.
You can even ring for service from the hotel's very good restaurant, Ah!, and eat outdoors - as long as you behave yourself.
There is also a free "travel agent" on site who can organise taxis, tours, visas, flights or train tickets. The brilliant Sky Train is a five-minute walk away, and with day passes at 120 baht ($4.65), there's no need to spend any more time than is necessary walking around in the Bangkok heat.
So if you're travelling on a budget and thinking about a booking, just remember: "The Atlanta caters to a certain kind of clientele and that is the end of the matter. No discussion. No compromise." Couldn't have said it better myself.
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Further information: The Atlanta Hotel is at 78 Soi 2, Sukhamvit Rd, Bangkok 10110, Thailand, phone (+662) 252 6069. There's information on the web but reservations must be made by fax to (+662) 656 8123 or 656 8124.
Shandelle Battersby paid her own way to Bangkok.