The National Museum of Australia launched Celebrating 50 years of Play School on Thursday, honouring a show that not only holds a special place in many Australian's hearts, but is also the second longest running children's television show in the world.

On hand to help cut the Rocket Clock cake was current Play School presenter Alex Papps and Play School veteran, Benita Collings.

Collings is one of the most recognisable faces from Australian television for three generations of people, having filmed 401 episodes of the children's program – the most of any presenter.

"When it first started for most of us it was like, 'oh good, it's another job, we'll eat that week'. Nobody really understood what the program was going to end up being in terms of its longevity of course, but the impact it was going to have," she said.

"And slowly bit by bit because of feedback and people saying things it was like, 'oh hang on, this is going to be huge'."

For current presenter Papps, who grew up watching the show, it was like a dream to get the gig, which is one of the most coveted in the industry.

"I can recall walking into the audition room and was introduced to the director and the producer and the pianist and I'm shaking hands but in my peripheral vision there is this imposing line of my childhood icons – there was Big Ted, Little Ted, Humpty, Jemima, Slush," he said.

"And I'm shaking hands and ... I said, 'lovely to meet you – is that the real Little Ted?' And they said, 'yes' and I said 'could I pick him up?' On one level it was silly, there was this row of stuffed toys but these characters had come to mean so much to me as a child and as they do to children today."

Opening on Saturday, the exhibition includes all of the show's icons.

There's not just one but two bears in there – Big Ted and Little Ted – along with Jemima and Humpty, plus the Rocket Clock, Flower Clock the original windows, and the house used to shoot the original opening sequence.

Once the exhibition closes its doors in Canberra on July 24 it will tour the country for two years.

Celebrating 50 Years of Play School is on at the National Museum of Australia from May 7 until July 24. Entry $4-$8 with under 5s free.

Play School Live is also coming to Albert Hall with Humpty's Showtime from July 8-10. Tickets at kidspromotions.com.au