Complex sentence: From a contemporary perspective many find it hard to imagine advocating the wholesale demolition of so much of the city, or how so many buildings we now recognise as significant and beautiful could have been earmarked for destruction.
Split into simpler sentences: From a contemporary perspective many find it hard to imagine advocating the wholesale demolition of so much of the city. Or how so many buildings we now recognise as significant and beautiful could have been earmarked for destruction.