New York City
As the oceans rose, many coastal cities were submerged. One such was New York City.
The beginning of the change happened well before the famine and virus, and much of the city was actually underwater before those events, but after the disasters there were too few survivors to bother maintaining the hybridized city. What now remains are the huge hulks of skyscrapers, peeking above the waters of the Atlantic. The inhabitants are only the skeletons of the starved, diseased, murdered and drowned.