Anyone who's been to Sydney recently will know that Kings Cross, the city's notoriously seedy red-light district, ain't what it used to be. There's very little that's seedy about the Cross these days; very few red lights being turned on.

Sydney's harsh lockout laws are helping to put an end to all that. Couple those restrictions with the inevitable creep of gentrification and you have a suburb in flux, one in which the old rules no longer apply. The Cross is a red-light district no more.

To me, that's a shame. I like red-light districts; they have character, they have edge. They might be seedy and sometimes a little scary, but they're usually areas of a city that wear their proclivities on their sleeve, where nothing is hidden or denied. Sometimes they're fun; sometimes they're ugly. But they're always interesting.

Though there are some pretty horrible red-light districts out there that I don't choose to hang out in, there are plenty I would recommend to travellers that are worth a wander just for the experience. The Cross is no more – but these dens of desire remain.

This is the classic red-light district, the one to rule them all. There are far more interesting and enjoyable parts of Amsterdam that I would spend a lot more time in; however, you have to call past De Wallen, just for the experience. Nowhere else will you see the things you'll witness in Amsterdam's red-light district, where prostitution is legal, regulated and even unionised, where drugs abound and British stag-do parties make nuisances of themselves. It is also, fortunately, pretty safe.

Reeperbahn, Hamburg

The whole world knows about De Wallen, but few seem to realise there's an equally extensive and neon-strewn doppelganger just as a few hundred kilometres away in Hamburg, Germany. The Reeperbahn is a notorious area filled with bars, restaurants and theatres, as well as sex shops, sex museums and strip clubs. It's also a largely safe space in which you'll find locals and tourists from all walks of life, most just there to wander and gawk.

Kabukicho, Tokyo

The Robot Restaurant in Kabukicho, Tokyo. Photo: Alamy 

If you want to experience the edge of a red-light district with the comfort of absolute safety, Kabukicho is the place to go. This notorious area in the centre of bustling Shinjuku does have a dark side, and it's possible to get yourself into an ugly tangle with the Yakuza if you decide to be silly. However, if you just want to visit the Robot Restaurant (as pretty much every tourist does) and then go for a wander, Kabukicho will treat you right.

Soho, London

Soho still has an edge, but in the same way that your reformed-hippie aunt still has an edge. It's pretty harmless. Though a few red lights still glow, and the area remains proud of its artistic and musical history (everyone from Mozart to the Sex Pistols has been based here), the entertainment in Soho these days mostly consists of theatre shows, fancy restaurants and good pubs and bars. It's worth a wander around here, however, for the history alone.

Schipperskwartier, Antwerp

What would a red-light district look like if all the questionable activities people visit to take part in were legal? What would these places be like if everything was regulated and respected? The answer is Schipperskwartier, a small "tolerance zone" in Antwerp that is clean, safe and pleasant. There are a few legal brothels here, as well a nice old church, some charming B&Bs, and an organic farmers' market on Sunday mornings.

Itaewon, Seoul

Itaewon isn't really a red-light district, as such. It is, however, an area that's traditionally been popular with Seoul's expat population, a part of town known for its "openness" in comparison to traditional local culture. You might not visit here for a proper Korean experience; however, if you're just up for a burger and a craft beer, and then a dance at a foreigner-friendly club, then Itaewon is for you.

Pigalle, Paris

Pigalle is a little like Kings Cross. It was once very seedy, a proper red-light district filled with shady types up to no good. These days, however, gentrification is rife, and many of the area's red lights have been switched off to make way instead for the mod-industrial exposed bulbs preferred by swanky cocktail bars and places that serve brunch. There are still brushes to be had with Pigalle's debaucherous past, but these days it's mostly very tame.

Bukit Bintang, Kuala Lumpur

So here's the deal: Bukit Bintang, a bustling shopping area in central Kuala Lumpur, is kind of a red-light district, and you will get an inkling of that as you wander the streets and fend off constant entreaties to have a massage. However, there are plenty of reasons to put up with that, and most of them involve food. In Bukit Bintang you can feast on excellent street-food style cuisine at Lot 10 Hutong, or take your chances on rowdy Jalan Alor. Whatever your choice, you'll eat well.

Geylang, Singapore

Mention you've been to Geylang in Singapore and people tend to raise their eyebrows. Geylang is seedy, and it is filled with brothels – however, the area has cleaned up its act in recent years, and as one of Singapore's more character-filled neighbourhoods, it's worthy of a visit. Take a seat at a pavement restaurant, order congee with frogs legs, and then sit back and people-watch to your heart's content.

The Deuce, NYC

This is another formerly notorious area that's more an attraction these days for its past than its present. The Deuce, a section of West 42nd Street in Manhattan, has been well and truly cleaned up since its heyday as a red-light district in the 1970s, when the area attracted all manner of characters and chancers with various intents. It's is now a major theatre district, and safe to wander at pretty much any time of the day or night.