Benefits of Epal Boxes
Types of Drainage Gullies
patio drainage gully

The Importance of Hanging Dustbins in Urban Environments
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 if rotated. A square cover, by contrast, could potentially fall through its opening if rotated diagonally.
The Importance of Toilet Grating Enhancing Hygiene and Functionality