Wallflower on the Abbey ruins

This is a wallflower (Erysimum cheiri) growing on the northern boundary of what's left of the ruins of the 12th-Century Abbey in Bury St. Edmunds. I took it about 5:30pm so the sun was weak and low in the sky and gently illuminated the golden petals and each flower on the wall just seemed to glow! These also smell wonderful- they're honey-scented with a slight peppery-ness too.