A 'little' ice, gravel, and water - Kettles
Kettles are holes often near river banks, or river terraces, and usually filled with water.
Kettles are formed at the tail-end of a de-glaciation flood carrying ice-blocks. When the flood subsides the ice-blocks among the gravel are 'gravel locked' - the gravel is now dotted with ice-blocks. These ice-blocks melt leaving holes in the gravel that slowly fill with water to form pools - thereby disguising the kettles, and making them difficult to identify.
Among the most obvious kettles in the upland of Mar is in Gleann Dhé a little downstream from Clais Mhadaidh - an untypical kettle - it sits on the edge of the river terrace. On the river-side, the kettle was cut away by the floods that created the river terrace leaving the kettle incapable of holding water, and looking like a small amphitheatre