Being circular also makes them easier to transport, as you can roll them along their edge, and square manhole covers have a larger surface area when made to the same width as a circular manhole ...

it will always fit securely on top of the manhole. Contrastingly, if the cover were square or rectangular, it could be turned in such a way that its diagonal would be smaller than the sides of the ...

In the UK many manhole covers are square. A 2018 paper in the International Association of Applied Psychology outlined a study of 736 adults to understand the effectiveness of the brainteaser ...

Another notable answer to this question — an answer that shows up consistently on internet searches — is that a round manhole cover, unlike a square one, will not fall back through its opening ...

this means that if a square or rectangular cover is turned diagonally, it could fit through the hole, posing a risk of falling in. Given this logical reasoning, you might wonder why some manhole ...