San Francisco city skyline. Credits: Lisafern, CC0, via Wikimedia Commons.
Great Ormond Street Hospital. Photo credits: David Hawgood (CC BY-SA 2.0).
Paris. Pierre Blaché by Pixabay
Image by Mario Zogheb from Pixabay.
Das Postfuhramt (Berlin). Photo credits: Matthias Süßen, CC BY-SA 4.0, via Wikimedia Commons