It’s 3.30am in the epicentre of Dublin’s nightlife: George’s Street. Revellers, some showing signs of inebriation, some not, leave the George nightclub and the rush of chic bars that have sprung up in the past year.

Some are trying to hail taxis or get a late meal in Charlie’s Chinese and Malay restaurant before eventually making their way home. However, others hang about waiting in anticipation, eager to continue the night.

By day, most are young professionals. There are teachers and solicitors. Others work in tech. Come Friday night, they are ready to let off steam. Even at 3.30am, the night is far from over.

Welcome to Dublin’s underground club scene, where those in the know can party until dawn, or later.

However, the parties are no longer basement bedsit gatherings in Rathmines with a few cans. Today’s “after-hours” are organised affairs, with entry fees – cash only.

The guests are chosen. Indeed, they are picked with care by the organisers, who cruise legitimate venues from 2am offering “wristbands” for an “after-party” at another venue on the other side of the Liffey.

People who look too drunk, too rough or just potentially troublesome are not invited to take part in a late-night, early-morning scene in Dublin that has re-emerged in the past year or so.

However, it has gained added impetus in recent months, perhaps an inevitable byproduct of better times, and more disposable income for those aged 20-35.

On the night in question, a Brazilian man is the lead promoter, taking €10 notes from those ready to party until sunrise. Once the guest has been “vetted” and the money handed over, a location is disclosed.

Some will make their way there on foot, or by taxi, but Dublin’s rickshaw drivers are keen to pick up such traffic. Most of the partygoers share rickshaws, partly to cut costs, but also to see who they will be partying with.

Box of pills

On the way to Parnell Street, the rickshaw driver makes small talk about how theIrish like to party and asks are we looking to buy drugs. He opens a locked box containing an array of pills, €10 a pop.

Declining, we made our way down Parnell Street. The street is quiet for a Saturday night, until a scurry of people are seen being ushered quickly under the shutters of a half-lit restaurant.

One young woman is new to Dublin’s underground scene. “To be honest, I only heard about this place from the lads in work. They were here on the May bank holiday weekend and said it was wild, so I want to see what all the hype is. I’m not into the pill-popping scene but I lived in Spain for a year so like clubbing until the early hours,” she says.

Most similar illegal clubs usher their crowd through a back entrance, but the organisers of this one are brave enough to let customers through the front door. They have little reason to be worried, since gardaí do not know about it.

“It’s like going back to raves in the early 1990s; people would just go out and party with each other,” laughs one of the bouncers as he ushers people in under the shutters.

A few hours earlier the restaurant had been serving its usual menus. Now, however, food is off the menu and punters are being served alcohol and drugs are everywhere.

Most punters arrive with wristbands. A few who do not queue to pay. IDs are not required. So long as people have money and there are no obvious signs they will start trouble, bouncers are happy to accept cash.

Downstairs a large crowd is already dancing. Late arrivals hand in their jackets behind the upstairs bar for €2. More than a decade after the smoking ban, the air is heavily smoke-filled.

The atmosphere is giddy, but the crowd is far removed from the neon-clad clubber of the 1990s rave scene.

The atmosphere is good and nonthreatening. These are the people who just do not want to go home at 3am and want to pull an all-nighter. Some “illegal clubs” have been regarded as fire hazards. This one less so.

American band Major Lazer’s hit Lean On booms as the venue, complete with couches and a makeshift dance floor, begins to fill up.

Dealers

“Bigger and better,” exclaims one of the young men dancing with his girlfriend, as he describes the smaller venues he has been to on previous nights out. Inevitably, drugs are proffered by dealers moving among the crowd: uppers, downers, ecstasy and cocaine. These drug dealers are blazer-wearing, clean-shaven professionals looking to make money on the side.

“It’s €10 for an ecstasy pill and €100 for a bag of cocaine,” the dealer tells a group of four tipsy girls sitting on the couches. They should, he said, only take half a pill each, just to be “safe”. Once served, the pill-poppers are content to dance the rest of the night away.

However, the hardcore demand more, including ketamine, a horse tranquilliser that has become the drug of choice for many.

One young woman says: “These clubs are not dangerous it’s just some fun and it’s the summer. Look around the room, there’s probably teachers and nurses in this room. It’s no different to European clubs, and if you go to Spain it’s not uncommon to be out clubbing until 6 or 7am.

“People take drugs here but people also take drugs before going to a mainstream night club like Coppers or The George, so why should we be targeted? It’s good, clean, illegal fun but everyone here is an adult, so what’s the harm?”

A handwritten drinks menu offers cans of Heineken, Guinness for €5, spirits for €7 or €8.

Clubs such as this first came to prominence in Dublin a few years ago. One such venue operated on Ormond Quay until late 2014, when it was raided and shut down by gardaí for trading as a nightclub without a licence. After that the scene was quiet until a recent rebirth.

The Garda Síochána said it had no information about or issues with illegal nightclubs in the city centre.

Leaving the venue at 6am, as milkmen begin deliveries, the majority of the crowd still have hours to run.

As the sun comes up over the city, a taxi driver says: “Sure they keep us in business, don’t they? Sometimes you get trouble. Other times you just pick people up who want their beds.”