Aussie singer and breast cancer survivor Olivia Newton-John is getting ready for another big challenge in her life -- conquering the Great Wall of China -- where she'll walk for three weeks to raise money to find a cure.

"It's going to be a life changing experience," the beloved "Grease" star told "Extra," adding, "It's going to be a test of endurance."

Olivia will have a video crew with her to document every step -- so stay tuned to "Extra" for her exclusive video diaries!

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