Yes, that’s actually why tort reform is such a big topic in American jurisprudence. Because property owners are liable if a bunch of kids suffer injuries on their property by falling into a hole, almost regardless of intent. Yes even if it’s properly secured with fencing, in many jurisdictions the trespassers sue for damages and succeed often.

Even failing to shovel the snow and having someone trip and injure themselves is enough grounds for some sort of tort liability.

To a lesser extent it’s true in Canada and the UK too I believe.

It's an "attractive nuisance." You'd better lock your hot tub and garage freezer too.