Ideas on spatial puzzles for a city walk

Background.
With the relaxation of covid-related restrictions, there was a need for intelligent city walks. Walk here is a moving between city objects by a certain (deterministic/stochastic) route.

I am looking for ideas of puzzles in the city in which you need to use basic knowledge of mathematics.

As examples of puzzles I can give:

• The Konigsberg bridges problem,
• Measuring the height of a building by the shadow (Thales method, described in the book by Jules Verne),
• A bottle search with a note using known coordinates (used in a TV show).

Subway Challenge

Question: What are puzzles can be proposed using different points of view like stairs, flagpoles, fountains, parks, bridges, cross-roads, buildings, monuments, metro/underground stations?