So, what is "Parkour" ("freerunning")?

We'll start off by using a video created by the New York Times called "The Women of Parkour" -- available via YouTube:


"In the sport of parkour, people leap off railings, jump over walls, and generally use the urban environment as their playing field." -- From the YouTube video post information.
Here are two other examples of "free running" in action. First, Kat -- a member of the group "Monos Urbanos" in Mexico:
And here's a Parkour chase scene from French film 'District 13'
-- don't try this at home (unless you're being chased by violence-prone gunmen intent on causing you harm...YMMV):

You might also think of the types of moves that Jackie Chan uses in his movies -- that kind of reactive martial-art style is also very reminiscent of certain aspects of Parkour.

And now you know why, when Maeve goes for a 'little run in the park,' she gets a mischievous gleem in her eyes...