Space savers for the young-ish
Knowing how building inspectors in the USA feel about spiral stairways, I am always appalled and delighted by the inspiring spiral I encounter in Latin America.
To save space, these twisters are used in everything from hotels (the concrete and red tile stairway below) to offices (the yellow steel stairway).
They are easy on the assent. But with low railings, and 60 years on my legs, I sometimes have to walk down these a little carefully.