Oh, and here is a pretty picture of the Massive young Star Cluster known as Westerlund 1, on one side of the nebula.
This is a composite of two DSS images, downloaded from the Aladin database and atlas
(don't pay any attention to the colours, as they bear no relation to reality)
Dana (user: Weltevreden SA) says that the cluster is only 3 arcminutes across.
The scene here is somewhat reminiscent of a close-up image of the very-very-compact cluster NGC 3603 and its attendant nebula; NGC 3603 is
also one of the most massive young star clusters in our own Galaxy.