For five brutal months in 2017 the black flag of so-called Islamic State fluttered over a captured city, and thousands of lives were destroyed. But rather than Iraq or Syria, this was a reality in Marawi, in the Philippines. Anna Foster travels to the heart of a devastated community - still off-limits to most - where ruined buildings cut through with shrapnel and bullet-holes are all that’s left of a once-thriving city.