Military organisers estimated that 70,000 people attended a 'Meet the Forces' day in Cardiff Bay on Sunday, at the end of the Nato summit Wales week.
Police have hailed the security operation - the largest the UK has ever seen - as a success, with 31 arrests made in total.
World leaders including Barack Obama left Wales on Friday, praising Newport and Cardiff for a warm welcome.
The Police and Crime Commissioner (PCC) for Gwent has praised police for their work during the security operation at this week's NATO Summit in Newport.
Gwent Police led the operation - one of the biggest ever undertaken in the UK.
A total of 31 arrests were made over the week, for offences such as trespassing and assaulting police.
Over 9,500 officers and staff were drafted in from 43 Forces for the event, which posed a bigger challenge than the London 2012 Olympics.
It saw police collaborate with intelligence agencies and military personnel to ensure the safety of sixty world leaders and their staff, as well as the public.
Gwent Police and Crime Commissioner Ian Johnston said it was a 'feather in the cap' for Gwent Police.
The response from the public has also been described as very positive.
Assistant Chief Constable Chris Armitt, who led the policing operation has thanked local residents.
Top policeman at Nato Summit says stun grenades were destroyed an hour before they were set to explode in path of world leaders.
'Meet the Forces' day was a crowd puller on Sunday as warships open up their decks in Cardiff Bay following Nato summit.
The day began with a spectacular fly-past over Cardiff and Newport by Nato aircraft.