Answer: Horse chestnut surface (macro)

What you're looking at

The horse chestnut is a large tree commonly found in parks, gardens, and woodlands across Europe and North America. Its most recognisable feature is the distinctive conker, that glossy brown seed kids have collected for generations, housed inside a spiky protective case.

This macro photograph shows the incredibly textured surface of the horse chestnut's outer casing. When magnified this closely, the bumpy spikes and intricate details completely transform the object into an alien landscape that bears little resemblance to what you'd see with the naked eye. The familiar conker becomes almost unrecognisable at this level of zoom.

Focus on clustered, blunt spikes with a organic, bumpy texture rather than sharp points when examining nature close-ups.

How players did

3 players made 5 guesses. It took 4 guesses before someone got it right.