A huge temporary wall has been built through one of London's most popular parks as part of rigorous security measures to protect US President Donald Trump while he's staying in London.
The heavy duty steel mesh wall stretches 800 metres through the north-west corner of Regent's Park which neighbours Winfield House - the official US Ambassador's residence where President Trump will sleep.
The 3-metre high wall is bolted to big solid concrete blocks every 4 metres, and UK police officers are stationed at 100 metre intervals along the wall.
It has been erected so President Trump's Marine One helicopter can land in the park. He's using the helicopter to travel between the London locations he'll visit because it's faster, safer, and means he will avoid seeing the protests.
There's no denying President Trump loves building walls: he promised during the 2016 presidential election to "build a great wall" on the US border with Mexico.
"Nobody builds walls better than me, believe me - and I'll build them very inexpensively [...] I will make Mexico pay for that wall. Mark my words," Mr Trump said at the time.
He's also built them around parts of his Scotland golf course near Aberdeen to block out the neighbours.
So, who has paid to build the big temporary wall around Winfield House? It remains a mystery.
The UK Home Office - which is in charge of policing and security for the visit - couldn't say.
"I don't know if it's something the Home Office would comment on," a spokesperson told Newshub, before referring the query to London's Metropolitan Police as it was an "operational matter".
However, the Met Police refused to discuss this operational matter.
"We never discuss security arrangements. I don't know who paid for the wall and even if I did, I wouldn't tell you," a Met Police media spokesperson said, before referring the query to the US Embassy in London.
Newshub also approached officers stationed along the wall, who had no idea.
The US Embassy press office number went straight to answerphone, and an email question is yet to receive a response.