The two massive mechanical creatures that have been wandering through the streets of Ottawa have become so popular that organizers of the event had to hire more security guards and volunteers to manage the crowds.

The last two performances on Friday and Saturday were "like two Canada Days," Guy Laflamme, executive director of Ottawa 2017, told CBC News Sunday morning.

Hundreds of thousands of spectators lined the streets to catch a glimpse of the 12-metre tall dragon-horse and the 20-metre wide spider — the hottest duo to visit the capital since Prince Charles and his wife Camilla.

The machines from France are the work of street theatre company La Machine and are in town as part of Canada's 150th celebrations.

Between 200,000 and 300,000 people are estimated to have watched performances on both Friday and Saturday. The same volume of people are expected to attend the final day of shows on Sunday, Laflamme said.

The opening day, Thursday, drew about 35,000 people.

Well over half a million people are projected to attend the four-day event.

We got adults to become kids again. - Guy Laflamme

Laflamme said he faced skepticism when he first proposed bringing La Machine to Ottawa, but today he's relishing in all the glory.

"I would say that right now I'm the proudest and happiest man in the world. I think this is for me, my biggest coup in my career and for the city this must be one — or the biggest — production ever," he said.

"We got adults to become kids again. It was so amusing to see adults running on the streets giggling and try to run in front of Long Ma to take photos."

Some spectators irked by Saturday show

Ottawa 2017 organizers are making changes to the show after the crowd exceeded capacity at the evening show on Saturday at the Supreme Court of Canada lawn.

"I don't wanna fight back, I have nowhere to go." Crushing crowd exceeds capacity at <a href="https://twitter.com/hashtag/LaMachine?src=hash">#LaMachine</a> show Saturday. (🎥 by <a href="https://twitter.com/Miss_Barbz">@Miss_Barbz</a>) <a href="https://twitter.com/hashtag/ottnews?src=hash">#ottnews</a> <a href="https://t.co/IdSFb49Wia">pic.twitter.com/IdSFb49Wia</a> —@giuseppelo

Less than 10 minutes after the 9:30 p.m. Saturday show was scheduled to start, the city tweeted the site had already reached capacity and urged people to avoid a section of Wellington Street.

Some spectators tweeted about the crushing crowd while others complained they couldn't see the beasts.

<a href="https://twitter.com/hashtag/LaMachine?src=hash">#LaMachine</a> insane crowd, impossible 2see. No wayout, police/enforcement <a href="https://twitter.com/hashtag/ottawa2017?src=hash">#ottawa2017</a> u can do better <a href="https://twitter.com/hashtag/sodisappointing?src=hash">#sodisappointing</a> <a href="https://t.co/bQYfKueJEK">pic.twitter.com/bQYfKueJEK</a> —@CLaidleyArn

"Great" planning <a href="https://twitter.com/ottawacity">@ottawacity</a>: all these thousands of people are watching a (poor-quality) SCREEN <a href="https://twitter.com/hashtag/ottcity?src=hash">#ottcity</a> <a href="https://twitter.com/hashtag/ottnews?src=hash">#ottnews</a> <a href="https://twitter.com/hashtag/cdnpoli?src=hash">#cdnpoli</a> <a href="https://twitter.com/hashtag/canada150?src=hash">#canada150</a> <a href="https://t.co/3JH0Nab4br">pic.twitter.com/3JH0Nab4br</a> —@OttSchools

Ottawa, may for once, be a victim of its own success. <a href="https://twitter.com/hashtag/LaMachine?src=hash">#LaMachine</a> is a huge hit, and as a result, we have crowds, big ones. —@TrashyParmer

Some people, however, didn't mind the crowds.

that was totally worth being squished & not being able to see anything tho 😂😂 <a href="https://twitter.com/hashtag/LaMachine?src=hash">#LaMachine</a> —@FatimaM_07

Changes to site plan for finale

Laflamme said the Supreme Court location "was not ideal" for the Saturday evening show, with more people than expected showing up.

"I would say overall there was 10, 15 minutes of intense challenge yesterday," he said. "As much as we were concerned about the limited space and some of the bottlenecks, our logistical plan worked very well. But the Supreme Court — we would have been better off to hold it on a different location."

Organizers have been working since 8 a.m. Sunday to make changes to the site plan for the final performance at the Canadian War Museum, which Laflamme said is a more accommodating space for the volume of people he is expecting.

One of the changes will be a "secure corridor" in the middle of the event space to make way for an easier flow of people. There will also be two large screens at the site to give spectators a better view of the performances.

In anticipation for the larger than expected crowds, Laflamme said he had to bring in more volunteers over the weekend to manage the crowds, making the total around 400 team members. More security guards were also hired for the event.

The RCMP also assisted Ottawa police officers in managing hordes of people downtown, including near Parliament Hill, and the ByWard Market.

Economic impact

Ottawa 2017 estimates a "major portion" of the expected $320 million economic boost from the increased number of tourists this year will come from the La Machine spectacle.

Jasna Jennings, executive director of the ByWard Market BIA, has also noticed a significant bump in foot traffic over the last three days. A couple from Arizona booked their trip to Ottawa more than a year ago.

Some restaurants, she said, ran out of food.

"Friday night I was turned away from at least three locations. I was trying to get supper but [restaurants] had literally run out of food," she said in an interview Sunday morning. "It was incredibly, incredibly busy."