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 US president is to visit a school during his two-day trip to Wales, the White House has confirmed.
He'll be joined by Prime Minister David Cameron on Thursday morning to meet with students.
Obama is the first serving American President to visit Wales.
He'll then go on to join other global leaders at the NATO summit for an official photo at the Celtic Manor Resort in Newport and attend a number of sessions.
That evening, there will be a working dinner on security challenges at the historic Cardiff Castle, which the president will also attend.
On Friday morning, the president will watch the NATO flypast which is taking place over Newport and Cardiff.
The White House confirmed he will stay in Wales until Thursday night and fly back to Washington on Friday.
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.