The bicycles are a dead giveaway. They're strewn across the high street, chained to anything that doesn't move. There are old bikes and new bikes, multi-geared racing bikes and single-geared trendy bikes. All are waiting patiently like chauffeurs for their art-viewing clients to return and ride them away into the night.
To find the bikes' owners, you just have to turn from the high street into one of east London's narrow alleys and there they are - hundreds of them.
Some are milling about in the street clutching cans of cider; others are moving in and out of galleries, chatting, conferring, talking serious art talk.
You don't even need to look at the artworks in order to be entertained tonight. It's like being on some sort of hipster safari, viewing these extravagantly plumed creatures of the night. You can even take photos, provided they end up on Instagram with appropriate hashtags.
There's a guy dressed like Boy George, only he probably isn't trying to look like Boy George. He's sporting a wide-brimmed felt hat, make-up around his eyes, and a baggy fluorescent jacket above jeans upturned at the cuffs.
Most of the other people milling through the street are variations on not-Boy-George's theme, with differing ratios of fluoro to stonewash, in clothes that could come in any shade as long as they're ironic.
This is the east London arts scene, and there are few better times to view it - and its enthusiasts - than the first Thursday of every month, when the achingly cool art spaces in Bethnal Green, Shoreditch, Hackney and Whitechapel stay open until late into the night.
The artwork is experimental, edgy and occasionally weird. The people looking at it are pretty much the same.
It's entertaining. It's also typically London. It's one of those events with just enough quirk to interest a niche crowd. And it's something that happens thousands of times across the city.
Grab a copy of Time Out to see what's going on. Somewhere in London tomorrow night is a pub offering "uke-aoke" - karaoke singing backed only by people playing ukuleles. That's marginally stranger than the "band-aoke" - karaoke backed by a live band - being offered somewhere else.
There's a bar hosting a club night called Raiders of the Last Tube, which promises to have the lights on and everyone out the door in time to catch, you guessed it, the last Tube home. It's like having a very responsible friend, or maybe your mum, partying with you.
What else? A friend of mine always talks about an event called Swap-a-Rama Razzmatazz, a club night during which punters hit the dance floor and, when the lights go out, exchange a piece of their clothing with someone nearby. "Some guys turned up in T-shirts with big holes cut out of the front of them," she says. "They thought they were hilarious."
Don't want to drink or dance or sing? Try Secret Cinema, a guerilla film event that ensures moviegoers have no idea what they're going to see or where they're going to see it. Hours before the show, guests are texted an address and told what to bring with them. The nights are themed around the movie being shown, and it's serious stuff.
On the Shawshank Redemption evening, punters were stripped and thrown in jail. They'd been told to wear clothes under their clothes. Good advice.
These little events are probably not the sort of thing that would bring someone to London in the first place, not like Big Ben or Westminster Abbey or Tower Bridge. But they are what would make them stay. This is a city where pretty much any wacky idea can find enough of an audience to blossom into reality. Want experimental art at midnight? Done. Want to be slipped contraband booze by a fake inmate? Sorted. Weird can become standard fare here. Who wouldn't want to live in a city like that?
When you're left behind in Australia, you can persuade yourself that your expat friends are just wasting their time in London, drinking their pay at the Walkies and the Sluggos and doing last-minute bus tours to say they've "done" Europe.
But what they're probably doing is enjoying the quirks of one of the world's great cities.
Back in Bethnal Green, the hipster safari continues. We take time to poke around the galleries, pretending to understand what we're looking at, but soon we're back on the street, milling around the fixie bikes and the irony.
Soon we'll head up back to the high street to dine out on Turkish-Indian fusion cuisine. If you think that's weird, you should see the people eating it.
What's been your experience of London? What's the strangest experience you've had overseas? Leave your comments below.