will flood in any given year. The Racetrack was vandalised in late 2016. Sailing stones The sailing stones are a geological phenomenon found in the Racetrack. Slabs of dolomite and syenite ranging from a few hundred grams (few ounces) to hundreds of kilograms (pounds) inscribe visible tracks as they slide across the playa surface, without human or animal intervention. Instead, rocks move when ice sheets just a few millimeters thick start to melt during periods of light wind. These thin floating ice panels create an ice shove that moves the rocks at up to five meters (16') per minute. The 2017 documentary Principles of Curiosity explores as its central theme the story of how the sailing stones' movement had been a mystery which came to be solved using the scientific method and critical thinking. Islands Two islands of bedrock outcrops rise dramatically above the playa's surface at its northern end. The larger landmark is The Grandstand, a high dark quartz monzonite outcrop, rising in dramatic contrast from the bright white surface of the Racetrack. The second 'island' feature is a smaller carbonate outcrop. Springs There are three areas of aligned depressions (intermittent springs) in the playa. Spinal Springs is in the central part of the Racetrack playa. It is 550 metres (600 yards) long and starts, at its northern end, with conical depressions only a few centimeters (inches) deep. Traced southward the depressions increase to ~5 metres (16') in width with scattered creosote shrubs. They then narrow and become shallower again, and finally disappear. Further north and south along this linear formation, there were several other depressions that may be a continuation of the Spinal Springs alignment. Edge Springs is an alignment of the depressions along the southeastern edge of the Racetrack playa. The alignment parallels the toes of alluvial fans along the base of the steep mountain range. Gindarja Springs is an alignment of depressions that consists of three large indentations aligned in a northwesterly direction within the Racetrack playa. Two are completely within the playa and the third is on the edge. All three are associated with significant vegetation. Visiting Access is via Racetrack Road, reached at the Grapevine Junction near Scotty's Castle. The 28 mile rough gravel road heading south-west from Ubehebe Crater is passable with non-4WD vehicles but requires high ground clearance. It rounds the western side of the playa to a parking area with descriptive