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.
Prince Charles will host a reception at the Celtic Manor Resort for world leaders and local people on the first day of the NATO summit.
The Prince will be joined by First Minister Carwyn Jones AM, Welsh Secretary Stephen Crabb MP, representatives from local councils and businesses and schoolchildren. The winners of the St David and Points of Light awards have also been invited to attend the event on 4th September.
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.