Continuing southeast as you leave the Palace you will encounter the remains of one of Palenque's many aqueducts. The main aqueduct at Palenque regulated the water of the Otulum stream, one of the most important of the city. There are numerous aqueducts located in different areas of the city.
The construction of the Main Plaza's aqueduct helped Palenque's builders to widen the surface necessary to construct large civic-ceremonial buildings and control the water course of the stream. The subterranean tunnel where the stream once flew is now almost completely collapsed, leaving the internal masonry construction visible.