The Madrid Open tennis tournament is underway.
It's taking place in a relatively new sports facility but what's really spectacular about it is the court.
Canadian player, Milos Raonic, calls it "smurf blue".
Photographers like Kike Del Olmo love the blue clay. "It's nice. You can see the ball better. The contrast is fantastic."
In addition, Del Olmo says, it's good to have something different to distinguish pictures of every other tennis match. "So for us (it) is fantastic."
Coincidentally, smurf-blue is also the corporate color of the insurance company sponsoring the Madrid Open.
But many players are unhappy. Any change can unsettle them, Del Olmo says, even the color. Plus, he says, the surface makes you run differently. Big stars like Novak Djokovic and Rafael Nadal hate it, saying it's too slippery.
But at least one star loves it. Serena Williams approves because she says you don't get as dirty playing on it as you do with red clay.
Our Geo Quiz question then: What is the name of the Madrid Open venue?
The Madrid Open facility looks like a big cube with a roof that slides off almost magically.
Hence it's name, "La Caja Magica", or Magic Box, which is the answer to our Geo Quiz.