Diana Nyad "Liberty Walk."

PENN'S LANDING (WPVI) -- A champion swimmer is trading in the water, for land, on a mission to get people of all ages, 'active and moving.'

Diana Nyad is the only person so far, to swim from Cuba to Florida.

She wanted to get more people exercising in the U.S. but found 'walking' was more of an interest, than swimming.

So she founded 'EverWalk', which is the largest walking initiative in American history.

Today, she kicked off a week long effort to the nation's capitol.

""We at Everwalk want to turn America into a full blooded nation of walkers. and today, we're walking from Philadelphia, not all in one day, in seven days, down to DC.""

Nyad calls the 7 day event the "Liberty Walk."

The challenge started at the Indepedence Seaport Museum in Penn's Landing.

The journey to Washington D-C... is 134 miles.