'The Sound of Music' child star shares the secret to cast's 60-year friendship

The hills are alive – with the sound of a reunion.

The former child stars of "The Sound of Music," who have remained friends for 60 years, recently reunited in Florence, Italy. Kym Karath, who played the youngest von Trapp sibling, Gretl, shared photos of the group catching up and enjoying bottles of wine on her Instagram.

"The Sound of Music in Florence – the five of us!" the 66-year-old captioned a group photo.

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