Left panel: density map of stars in boxes 2 and 3 of Fig. 3 corresponding to stars on the RC and RGB. The position of the control field ConF1 (see Sect. 3.2) is marked with a red quadrilateral. Right panel: density map of stars in box 1 of Fig. 3 corresponding to stars on the upper MS. The shell-like featured detected in the Canon 200 images is marked with label a. The map reveals two new features: a spiral arm-like structure (label b) and an outer, small overdensity of young stars (label c) in the vicinity of the globular cluster NGC 362.