There are very tight minimum altitudes during the approach that have to be carefully monitored at all stages. There is no latitude for slackness in commencing descent at each stage. The approach brings you over the city too. Long straight approaches over mountain ridges often just won't work- the GPWS would not like it and cause go-arounds. Places that spring to mind are Mauritius 13 over the centre of the island and steep approach paths, and Seychelles where we used to get away with it on a visual approach, but you couldn't do an instrument approach on a straight in. Seychelles was very stimulating- you had to handfly in the dark a curved approach monitoring lighthouses- just like a yachtsman- until you could make out the runway nestled against enormous mountains. In daylight standing at the airport and looking up, you suddenly discovered what you'd been mussing with! Very sobering.