Example images of three radio sources at C-band (left-column), X-band (middle-column), and K-band (right-column). The position of the H II region is marked with a plus. Upper, middle, and lower rows: maps for the compact H II region G032.7441−00.0755, the extendedH ii region G035.4669+00.1394, and the H II region G043.1665+00.0106 located in a cluster (see Sect. 3.1), respectively. C-band images are from the CORNISH survey. The white contour levels of each image are equally spaced by 5σ and start at a level of 5σ. The green outline shown in the lower row shows the polygon that was manually drawn around the H II region located in acluster. The image size and beam size are shown in the upper-middle and lower-left of each image. The C-band, X-band, and K-band images for the whole sample are available in electronic form at the Zenodo via https://doi.org/10.5281/zenodo.4293684.