The "Wall" is part of the much bigger "North America Nebula" ( NGC7000), where it is standing for "Mexico".
It consists mostly of glowing hydrogen ( red) and oxygen ( green-blue), which gives the whole nebula a pinkish color.
Canon EOS 20D Modified Canon 20D mounted on a Vixen R200SSDG(8"/F4)+ Televue Paracorr + Astronomik UHC filter + IDAS LPS ( as an IR blocker). 25x300sec/ISO800. Calibration and stacking, averaging, color balancing, sharpening in Images Plus and Photoshop CS2.