 Toniná is located at an altitude of 800 to 900 metres ( 2 @,@ 600 to 3 @,@ 000 ft ) above mean sea level in the Chiapas <unk> of southern Mexico , some 40 miles ( 64 km ) south of the contemporary Maya city of Palenque , Toniná 's greatest rival throughout its recorded history . Toniná is separated from Palenque by mountainous terrain and the site core is located along an easily defended ascending limestone ridge immediately to the west of a seasonal tributary of the <unk> <unk> , one of the two rivers forming the Ocosingo Valley . 
