If you needed 60m of straight, flat, reasonably decent hard paving...

[Topplace]

To do some exercise drills on, where would you head for?

I'm old and not especially fit, these are exercises to help with rehabilitation. I don't especially want an audience....

A business park (offices) at the weekend

Local disused runway

Reservoir

Skate park early morning (like even before toddlers are up and out)

Local cycle/walking path - people but they’re all moving not loitering watching you

Sidenote - local leisure center car park during lockdown was heaven for my learning-to-rollerblade child!

Have a look and see if there are any old railway paths near you. Often these are surfaced and not the sort of places people loiter so although people may pass you they won't see you being there for a period of time.

In my small town there are lots of snickets that are well paved, fairly broad and quiet during the day.