Aqueduct

This "Aqueduct of Guadalupe" was built in Jun 1743 and completed in July 1751 during Spanish government.

When it was finished it measured 6.2 miles and it was built to provide water to the village of Guadalupe where the Basilica is located. 

Parts of it were subterranean but most of it can be seen and it's now a national historic monument.

You can still see most of it today and it's in good shape.