I’m a little surprised no one has suggested that all marked land marks be within a few miles of each other, so as you over fly one, the next one is already in sight.
Nah, too easy, too boring.
Seriously though, you can't always do that. Over East Anglia, on a clear day from FL95 in a C172 you can see pretty well the whole coast, so
any navigation consists simply of spotting your destination and pointing at it.
But on a bad day, scraping along at 1500' beneath the cloud with visibility on your minimum, you might be able to see nothing for minutes at a time but lots of wiggly little roads, all alike, lots of tiny little villages, all alike, lots of wiggly little streams, none of them on the map. So even if you wanted to you couldn't pick landmarks within sight of each other as there simply aren't any.