Around 1,000 protesters have marched through the streets of Newport ahead of next week's Nato summit.
More than 150 heads of state and ministers will attend the two-day event at Newport's Celtic Manor Resort.
Security for the summit will be provided by 9,500 police officers drawn from 43 UK police forces with 12 miles of security fencing already in place at keys sites in Cardiff and Newport.
The event will be "uncharted territory" for police - while Wales' First Minister Carwyn Jones has said it will be "momentous" in his country's history.
However, its presence in the principality - and the UK - has been met with strong opposition from a number of anti-war groups as well as left-wing organisations.
A large crowd gathered outside Newport Crown Court at around midday before going on a march through the Welsh city.
As well as strong Welsh contingent, protesters came from as far as Washington in the USA, Belgium, France and Ireland.
Groups including Stop the War organised coaches with campaigners being driven in from London, Birmingham, Norwich and Newcastle.
Among those taking part in the march was seasoned CND veteran Bruce Kent.
He said: "Nato's continued expansion has brought about the current problems with Russia.
"If you put yourself in their shoes, you would be concerned at the growing military presence on your doorstep.
"We need to think about peaceful ways of resolving problems not ramping matters up further with the sabre rattling that Nato have been doing.
"We need to say no to Nato and no to nuclear weapons.
"The money being spent on Trident would far better served in health or education."
Also taking part was the Wales Green Party leader Pippa Bartolotti.
She said: "The Nato that so many people remember as a force for defence has turned into a force for aggression without anyone really being aware that this subtle change has happened over the last 10 to 15 years."
Plaid Cymru Assembly Member Bethan Jenkins, who was also present, said Wales' First Minister Carwyn Jones had continued to dodge the issue surrounding people's concerns over the summit.
She said: "He has repeatedly refused to speak about the situation regarding Nato saying it is a non-devolved matter - but then has been happy to speak at length about other non-devolved matters before.
"Much has been said about how Wales will benefit from the summit, but I honestly fail to see how it will - given the massive disruption it will cause as well as its cost.
"Wales is a peace loving nation and has a long history of pacifism."
The march came just ahead of a counter summit tomorrow as well as a peace camp set up in the city's Tredegar Park.
Newport Council said it had been given assurances the camp will be a "peaceful encampment" and would not interfere with the park's normal activities.
A spokesperson said: "Newport City Council is continuing to work with partner agencies to monitor the situation and minimise the impact of such a camp."