This chimney on the rear gable of a cottage is in poor shape.
The pointing (mortar between the brickwork) has eroded and the chimney has started to lean forwards slightly.
It could be an expensive job to repair as scaffolding for safe access may be needed. The mortar needs repointing. The chimney pot to the top and “flashings” around the base of the stack need checking to ensure they are secure (to avoid rainwater penetration and storm damage). Close inspection may even reveal the need for partial rebuilding so the chimney does not beocme dangerous.
So, remember to look up every now and then to ensure everything is as it should be.