The stream has become overgrown during the Summer, so we went to inspect it this morning.
The wood across it is the squirrel bridge. Great for squirrels to cross safely, also for a neighbours cat to cross after the wild birds that we feed. The squirrel bridge is also an escape route for the same cat when next doors dog see's it.
Amie isn't so hot at chaseing cats over bits of wood, so takes the easy way over.