Bindi and Robert Irwin paid tribute to their beloved father on Steve Irwin Day.

On Sunday, the brother-and-sister duo took to Instagram where they honored the late conservationist, marking the international event that celebrates his life and legacy.

"Thinking a lot about my Dad today and the impact that he made on our planet, inspiring an entire generation," Robert captioned a throwback snap of himself, Bindi and the proud patriarch.

"I also think about what a truly amazing dad he was," the 17-year-old continued. "Through a lifetime captured on camera and stories from my family and those who knew him best, I'm able to remember the special times with dad."


Steve Irwin

Steve Irwin with his children Robert (left) and Bindi, circa 2005.  (Photo by MeganSlade/Newspix/Getty Images)

"I still look up to him every day and while I miss him so much, it means the world to me and my family that each year we can have a day for the world to celebrate what he stood for," the wildlife photographer added.

Bindi also shared her own heartfelt post with a photo of herself all smiles as she’s held by Steve by the ocean.

"Your legacy will live on forever," wrote the 23-year-old. "I love you for even longer."

Steve, who famously hosted the internationally syndicated show "Crocodile Hunter," died on Sept. 4, 2006. The barb of a stingray pierced his heart while he was filming a documentary at the Great Barrier Reef in Australia. He was 44.


Robert, Terri and Bindi Irwin

Robert Irwin, Terri Irwin, and Bindi Irwin have worked together as a family to keep the late patriarch's legacy alive. (Getty Images)

Bindi was just 8 years old when her father was killed.

Back in September, she wrote an emotional post on Instagram that accompanied a photo of her daughter Grace Warrior, now 7 months old.

"This sweetheart has been watching her ‘Grandpa Crocodile’ on the projector at our camp here on the Steve Irwin Wildlife Reserve," wrote Bindi. "She lights up when she sees him on screen."

"I wish with all my heart that Dad could hug my beautiful girl," she shared. "It’s been 15 years since he passed away. I hold on to the thought that he’s her guardian angel now, watching over the most special part of my life, Grace Warrior."


Bindi Irwin

Bindi Irwin and her husband Chandler Powell welcomed their first child, a daughter named Grace Warrior Irwin Powell, on March 25.  (Bradley Kanaris/Getty Images)

In February, Bindi told ET that Steve would have been "over the moon" to have his first granddaughter.

"He would’ve been a good, good grandpa," said the expecting mother at the time. "I don’t think we would’ve ever seen our daughter. He would’ve just whisked her away into the zoo and it would’ve been perfect. But it is so nice that we’ll be able to introduce her to her grandfather through all of the documentaries. It’s really special."

She previously told The Bump that her daughter's name pays tribute to her father.

"My dad was the first person to create the term ‘Wildlife Warrior,’" Irwin explained. "Being a Wildlife Warrior means to stand up and speak for those who cannot speak for themselves. We’ve been referring to our daughter as our Baby Wildlife Warrior. I know in my heart that she will forge her own path to make our planet a better place."

The Associated Press contributed to this report.