The irregular distribution of light in this beautiful part of the sky is due mainly to clouds of dust that dim the light of vast clouds of stars that make Sagittarius one of the brightest parts of the Milky Way. The Lagoon nebula is an illuminated part of such a dark ('molecular') cloud and it reveals the dust as dark lanes and globules silhouetted against the luminous gas. This structure is exaggerated here by copying the original red-light plate through an unsharp mask. Within the nebula is the scattered young star cluster NGC 6530, recently formed from this material, though the centre of star-forming activity has now shifted westwards from the cluster to the brightest part of the nebula, around the tiny Hourglass Nebula. The Lagoon nebula is clearly visible to the unaided eye on southern hemisphere winter nights, in a dark part of the Milky Way close to the great star clouds in Sagittarius.