Look closer, and other worlds are present too. The rooftops here are nearly all covered in orange tiles, which fade with age, slipping into burnt ochres and deeper, brown-reds. Even as the clay ages, the tiles gain other colours — the greens, greys, oranges, yellows and startling whites of moss and lichen, cloaking and coating, spreading and demonstrating the cleanliness of this air, some of the best in the world. The irony that, outside, the air pollution index is at 0 but, inside, the constant battle against the spores and spreading black mould means that, on days we cannot open the windows, the air just feels wrong, is not lost on me. The very damp and freshness which brings this welcome breathability, means the mould flourishes.