The travel Barbara Walters has done for work has far surpassed her travel for pleasure, but that's about to change.

She's planning her first trip to South Africa in October, with her daughter, and the timing wouldn't work if she were still committed to her co-anchor role on "20/20." The ABC newsmagazine's 26th-season premiere on Friday is a two-hour farewell salute to Walters's 25 years on the program.

"I have somewhat mixed feelings," Walters said of her departure, "but I know it's the right thing for me to do at this time. . . . I can take a breath and not have the week-in, week-out [routine]. After 25 years, it was enough for me."

Walters joined "20/20" in a hasty makeover following the program's debut in the summer of 1978. The initial anchors were fired, and Hugh Downs was brought in the second week. "He did maybe the first year alone" as host, Walters said, but Roone Arledge, then-president of ABC News, felt the show would be better with two people.

"Hugh resisted at first, and told me so, but we're very compatible," Walters said. She was formally named the show's co-host in 1984.

Two decades later, Walters is ready to exit, a move she had been formulating for some time.

"It wasn't just, 'Oh, you know what? I should leave.' I really didn't ask a lot of people their advice before I talked to [current ABC News President] David Westin about it. I just felt there was nothing else on the program that I wanted to do. When my friend Beverly Sills left the Metropolitan Opera, her husband gave her a ring, which she gave to me years later. I still have it, and the inscription says, 'I did that already.'"

But Walters isn't leaving TV entirely. She'll still be on "The View," the weekday ABC program she produces and co-hosts. "For me, that's the whipped cream. I love those women, and I love doing that show. Then I have to do a minimum of four to five specials a year for ABC. Two of them are programs we've been doing for years and years. One is 'The 10 Most Fascinating People,' which is on in December, and the other is our Academy Awards-night special."

Elizabeth Vargas will assume Walters's "20/20" seat on Oct. 1, but Walters anticipates returning from time to time. "Occasionally, there will be a story I will do for the show," she said. "It's not as if I'm never going to touch it again. It's just that I don't have to do it every week."