UPDATE, March 3, 2025: I got a photo of the sign. It is intriguing, but not particularly illuminating:

When I was on my run at Burnaby Lake, I saw this partial enclosure near the 5K marker, which was not there the last time I passed through.

A few things as observation:
- I didn’t notice the red sign until after, which may very well reveal its purpose.
- It’s cute that the gate is padlocked, since the entire back is open.
- I like to think it’s ultimately intended to be a jail for misbehaving geese.
- I will take a photo of the sign and report any further changes after my next run.