This beautiful construction is a Blackbird's nest. Yesterday it contained some eggs, and was carefully hidden in a pile of wood and sticks. This morning I found it, partly pulled from it's hiding place, with the eggs broken ( and eaten) and strewn on the ground. Probably Magpies, possibly one of the two Foxes I saw earlier.
Luckily, we have lots of cover in the garden. It is possible this pair may try to nest again.