It was love at first sight when Marlo Thomas and Phil Donahue met on the set of his eponymous talk show in 1977 — and they still find each other just as fascinating today.

“For us, it is always about finding new adventures together, like climbing China’s Great Wall,” Marlo recently told Closer.

phil donahue and marlo thomas

Phil and Marlo in April 1979.

The esteemed actress, 78, who first found fame on TV’s That Girl in the 1960s, confided that “spending time together” is critical to a happy marriage.

RELATED: Phil Donahue and Marlo Thomas on 35 Years of Marriage: ‘It Just Keeps Getting Better’

And although 2016 has barely begun, Marlo and Phil, 80, already have lots of plans.

To read the full story on the happy couple, pick up the new issue of Closer Weekly, on newsstands now!