PROTESTERS are converging on Blackheath for a week-long camp.
The location of Climate Camp had been a secret, but 1,000 environmental protesters have now started to set up camp on the heath.
Police have said they will send 500 officers to the event, which aims to draw attention to industries which protesters say are damaging the environment.
Student Tom Costello, 21, from Forest Hill, is taking part in the event.
He said: “It’s great - everybody’s just arriving.
“There’s probably 1,000 or more people here.”
He added: “We needed a site that was big enough to hold 3,000 people.
“I think we chose it because we’ve got such a good view overlooking the city and that’s what the message of Climate Camp is.
“We’re holding the city to account.”
Organisers of the camp said this year's venue symbolised the financial and corporate centres of power, and was within the floodplains of the River Thames, which activists warned was at risk of bursting its banks as climate change escalated.
One of the organisers said: "Having previously camped at sites of climate crime such as Drax, Heathrow, Kingsnorth and the Climate Exchange on Bishopsgate, today the Camp for Climate Action is setting up camp at the doorstep of the economic and political systems that are fuelling catastrophic climate change."
One of those joining the camp, Lizzie Jacobs, said: "This year the camp is pitching its tents at the doorstep of the root causes of climate change. That's why we're in London - it's the hub of climate business and a symbol of the failed political and economic systems that are causing climate catastrophe.
"I'm really looking forward to the next week - it will be packed with opportunities to learn and to build a movement that is taking action on climate change.
"Climate change is relevant to absolutely everyone, so everyone is invited to come down to the camp to find out more and join together to demand and create a more sustainable society."
The first of the campers arrived on bicycles at the entrance of the site, close to historic Greenwich Park.
The so-called Camp for Climate Action is on common land, where in 1381, preacher John Ball gave what was probably the country's first speech against class oppression.