Nickelodeon characters took over Sydney, Australia’s Hyde Park Sunday to host the official Summer Playground in honor of Australia Day.

The free event features live performances, superhero activities and character meet-and-greets with Nickelodeon characters including SpongeBob SquarePants, Dora the Explorer and the Teenage Mutant Ninja Turtles.

SpongeBob even replaced his SquarePants with Aussie boardshorts in honor of the national holiday.

At 12pm, the Nickelodeon characters and performers joined Nick Jr.’s Sam Moran for the Salute to Australia, which saw the whole nation unite and sing the national anthem.