No, these blue patches on the surface of Mars aren't Martian lakes or swimming pools. They are deposits of volcanic sediment carried by powerful winds blowing across the Red Planet's surface.
The photo, taken by the European Space Agency's Mars Express orbiter, shows several of the craters that dot the Arabia Terra region of Mars.
Winds blow as fast as 62 miles per hour on Mars. Just like on Earth, strong gusts erode the landscape over time. The photograph shows how winds wear down the sides of craters, including the large one on the left, which measures 43 miles across.
The massive dust storms also deposit minerals, like the volcanic, basalt-rich sediment found in the craters.
Those brilliant blue patches would not be visible to a human observer floating above the planet. Instead, they are an optical illusion caused by how the image was processed. Still, it makes for a pretty picture.