What kinds of unconventional chess problems exist? - Chess Stack Exchange

What are some unconventional chess problems that ordinary chess engines can never solve? I'm attaching two examples below so that you can get an idea. My students seem to love these puzzles. I'm

If Mr. Niemann is not cheating, the magnitude of his achievement

List of chess variants - Wikipedia

English 'calvert Pattern' Boxwood & Ebony Chess Set, 19th Century

Unconventional Approaches to Modern Chess 2 - Schachversand Niggemann

Given a layout of chess pieces like in a tactics puzzle, how can one

Chess (Tabletop Game) - TV Tropes

Apart from the 8 queens puzzle and the knight's tour, which other

opening - Danish Gambit normal variation - Chess Stack Exchange

The Paradox of the Two Knights - The Gower Initiative for Modern

strategy - If the back row of white pieces is moved to be in front