Climate activists have been training ahead of what they say will be 48 hours of direct action against energy firm Cuadrilla, which is carrying out test oil drilling in West Sussex.
Protesters at the Reclaim the Power camp at Balcombe have been learning how to use metal tripods to scale heights in readiness for action on Monday.
Cuadrilla has already suspended drilling during the six-day camp.
Residents in the village have said protesters plan to enter the site.
In the climax to a weekend of activism, during which hundreds of people gathered at Balcombe, more than 1,000 protesters congregated at the village railway station on Sunday afternoon to march to the Cuadrilla site.
Activists banged drums, held banners and chanted anti-fracking messages. Police guarded the secured site and a helicopter hovered overhead.
Campaigners chanted: "This is what democracy looks like," and also shouted: "There are many, many more of us than you."
After the protesters began to disperse from the Cuadrilla site on Sunday evening, Sussex Police thanked them for their conduct.
Supt Lawrence Hobbs said there had been a "carnival atmosphere" among the demonstrators during the afternoon.
"They have shown that upwards of a thousand people can make their point passionately, but peacefully, and I sincerely hope that it has set the tone for the next few days," he said.
He said three people had been arrested over the weekend in "isolated incidents" that were "away from the day's events".
Two men were arrested in relation to public order offences allegedly committed last week. One, a 23-year-old, was charged, while the other was bailed until next month.
A woman was also arrested, on suspicion of trespassing on the railway at Balcombe station.
Speaking about its plans for Monday, the No Dash for Gas group said more than 800 people were forming "civil disobedience plans", details of which remained "top secret".
A spokeswoman said protesters had filled out "matchmaking" forms to put people into groups. Campaigners used the forms to indicate to what extent they were willing to risk arrest, how mobile they were, and what activities they were most interested in.
Listed activities included climbing things, standing one's ground, getting through or over fences, looking after people, providing entertainment, or documenting action, she said.
BBC reporter Roz Upton said: "Protesters at the camp have been doing tripod training.
"They have got tripods made out of three pieces of metal that allow them to get to a height, and they climb to the top of that."
The campaigners fear the oil drilling could lead to fracking - or hydraulic fracturing - a technique designed to recover gas and oil from shale rock.
There are concerns the process contaminates groundwater and causes earth tremors, but supporters say fracking is safe if done properly.
Cuadrilla is drilling a 3,000ft (900m) vertical well and a 2,500ft (750m) horizontal bore, at a site south of Balcombe. The firm said fracking for shale gas there would require fresh permission.
Camp organisers said about 600 people were at the site on Sunday afternoon, and the camp kitchen had fed about 800 people on Saturday night.
Last week, Balcombe Parish Council issued an open letter warning campaigners not to carry out illegal activity. The council said direct action was likely to include an attempt to enter the site.
Cuadrilla suspended drilling on Friday but said work would resume at the site as soon as it was safe.
On Friday, The BBC's John Moylan said the company had made the well safe, secured the site with a reinforced fence and gone into "lockdown mode".
Sussex Police has endorsed the energy firm's decision to stop drilling.
The force said: "Given the health and safety risks associated with it being an industrial site if access is gained by trespassers, we believe their decision to be a wise one."
Cuadrilla chief executive Francis Egan said: "I think the threat is to access the site and to potentially damage equipment on the site."
He said the firm had concerns for the safety of its workers and anyone who went on the site.
"We strongly request people not to do that because it's not safe to do it."