Might be temping but being near a water source is excellent. You can almost breath the water in. There’s a healthy amount of negative ions released into air when waves and water clashes, or when it rains, it is felt as that freshness… Read about negative ions. walking bare foot is also that, absorbing negative ions from the soil.
Think like that and surely you can find more of that… Let’s see.. High mountain winds are strongly charged… Cold places, maybe some caves, maybe some of those natural salt caves.