Our excursion in Puerto Chiapas took us to these ruins.  They are on a riverbed, large, and 2000-3500 years old!  There have been multiple excavations.  We saw stones with carvings and perhaps glyphs.  It was quite hot and humid and I didn’t get to see as much as I would have liked.  For me, the significance of these sites is that we preserve them, study them, and realize how connected we are, to our past and therefore to our present.