Officers say that 'large' volumes of vehicles heading towards Lake Vyrnwy and Llanrhaeadr Waterfall were turned around on Friday.
Welshpool police said: "Fines have been given out for breaching Covid-19 regulations. In addition, five traffic reports have been submitted for vehicles with no insurance and no licence."
Patrols close to the beauty spots were made as the Welsh Assembly leader, Mark Drakeford, defended the decision not to change the exercising from home only rule in his three-weekly review of lockdown rules for Wales.
He said that the reason for insisting that exercise should start and finish from home was so that there was no repeat of the problems of last year when beauty spots were inundated with day trippers travelling long distances to exercise.
Mr Drakeford did however relax the rules to allow two people from two households to exercise together – but he said this must be exercising not socialising.
The waterfall at Llanrhaeadr was swarmed by more than 3,000 people on one day last summer, proving popular after the first lockdown restrictions were lifted.