I was in Iceland this past June and the mismatch between the number of tourists and the infrastructure at the national parks and scenic overlooks/stops was enormous.

I have no idea what the right number of tourists for Iceland is but at several locations the facilities (restrooms, food services, shop) were small and completely overwhelmed by the number of busses that were stopping in quick succession.

I was on a cruise and unfortunately the logistics of port calls tends to create very bursty traffic patterns with large number of tour busses disgorging visitors in quick succession at these under-sized locations.

For example the facilities at Goðafoss were undersized: https://www.google.com/maps/@65.6860127,-17.5395264,3a,37.5y...

On the other hand the facilities at Geysir were much better: https://www.google.com/maps/@64.3100169,-20.3013397,3a,75y,1...