MAHLI throws some light on the drill hole in Windjana.
NASA description: Using an onboard focusing process, the Mars Hand Lens Imager (MAHLI) aboard NASA’s Mars rover Curiosity created this product by merging two to eight images previously taken by the MAHLI, located on the turret at the end of the rover’s robotic arm. Curiosity performed the merge on May 14, 2014, Sol 629 of the Mars Science Laboratory Mission, at 13:02:46 UTC… [More at link]
Sol 629 raw images (from all cameras), and Curiosity’s latest location map.