As far as I'm aware, the only racing circuit in the world to sport powder blue armco barriers, very distinctive. Up there on the list of my favorite circuits and one I've actually visited, though never for a race (but did witness a blue formula car testing there in the late '70s...Tyrrell?).
The shot shows the uphill "Esses" complex, the tower in the foreground is the location of the original start/finish line with the original pit exit just to the right of the tower. The quantity of barrier in this area as noted by
@BlueC, particularly beyond the crest of the hill, is there as a direct result of incident (as is true with most racing venues).
During run-ups to the 1973 F1 USGP, driver Francois Cevert clipped the inside curb of the left hander, which shot his car across track into the right barrier. The car spun violently back to the left, striking perpendicular to and splitting the left barrier, then inverted and rode the top of the rail, effectively bisecting Cevert in the cockpit.
Cevert's teammate was Jackie Stewart. He, as well as the team, withdrew from the event out of respect for Cevert. The race would have been Stewart's 100th and final in F1, having already clinched his 3rd F1 driver's championship a few races earlier in the season and made the decision to retire from racing (though hadn't told anyone). Cevert would have assumed #1 driver duties for the team the following season and had pretty good odds of winning a driver's title at some point in the future.