Those who visit the Fairy Glen are currently puzzling over the state of the small loch at the foot of the glen.
Theories on what is causing the strange streaks include the presence of iron ore or an algal bloom.
The mysterious streaks dissipate if the loch is windswept, but are visible when the surface is still.
Inquiries are currently being made and it has been reported to the Scottish Environmental Protection Agency.
Photographs from Fairy Glen Facebook page.