This cluster is located inside the large Coalsack dark cloud - unfortunately, CCD cameras pick a lot of faint stars in front of the famous Coalsack cloud...
The large dark clouds visible are a part of the Coalsack, the bright star in bottm left is Alpha Crux, a nice double star resolved in this image. The NGC4609 cluser is a bright star knot in the bottom right quarter. Few nice planetary nebulae are also visible.