Police in the Brecon Beacons turned away more than 1,000 cars last weekend as tourists from as far away as London and the Midlands flocked to beauty spots despite lockdown restrictions.
Visitors were attempting to get to Glynneath, the area known as Waterfall Country.
Dyfed-Powys Police say many of those who were stopped claimed they thought the travel rules were the same as in England, while some deliberately ignored restrictions.
Almost 75% of people fined for breaching Covid-19 restrictions in Powys have been from outside of the force area.
We have had people shrug their shoulders and say ‘I thought it was ok to travel’ or ‘I didn’t think I would be caught.'
But people in England can travel as far as they want for exercise and to access beauty spots.
Police are eager to remind people to "make the best choices to protect public health in Wales".
Chief Inspector Ellis said: "I want to emphasise to any potential visitors that until there is clear direction that you can travel to Wales, stay at home or local to where you live.
“These areas will still be here to visit when restrictions are lifted.”