I watched a lot of old Time Team episodes lately and this looks like more of the same from the era. Really nice, complex looking work but overall what can be expected for the time period. Cool that it's so well preserved though and hasn't suffered from having a plow or seismic event turn it into a puzzle.
Classics right there! We've got a long linage of this kinda stuff now from browser resets to full stylesheets to well specified content just for testing any of the above on. I love it! Simple. Consistent. And now more powerful than ever with the help of variables.
Might be fun to take all the w3 core styles rebuild them with modern CSS features. Maybe add some HTML5 elements to the test docs as well.
Ice age trail - https://www.iceagetrail.org
Superior hiking trail - https://superiorhiking.org/
John Muir trail - https://www.johnmuirtrail.org/
Long trail - https://www.greenmountainclub.org/the-long-trail/
Pacific Crest trail - https://www.pcta.org/
Hayduke trail - http://www.hayduketrail.org/
Arizona trail - https://aztrail.org/