18th c. canal found in Madrid subway expansion

The expansion of Madrid’s Metro Line 11 has uncovered an exceptionally long and well-preserved stretch of an 18th century canal. At the site of the future Madrid Rio station, archaeologists unearthed the longest section of the Royal Canal of Manzanares ever discovered.

A river channel connecting Madrid to the Tagus River and thence to Lisbon and the Atlantic was the brainchild of Philip II (r. 1556-1598), ruler of the Spanish Empire and later King of Portular. His engineers conceived a canal 12 miles long parallel to the Manzanares River which empties into the Jarama River which empties into the Tagus at Aranjuez. The canal would have connected to the Jarama so boats could have gone from the canal to one river, to the next river, to the ocean. His ambitious plans went nowhere, falling prey to his endless series of debt defaults, wars in Italy, the Low Countries, and not one, not two, but three attempts to invade England by sea.

It was Charles III (r. 1759-1788) who revived the idea and implemented it two centuries later. Construction on the canal began in 1770 and while it was never completed, it did see use to transport supplies and materials to the new factories in the south of Madrid. Only 13.6 miles of the canal were finished. It was 46 feet wide and just 10 feet deep. Flat-bottomed barges started from a pier near the Toldeo Bridge in Madrid, then traveled southwards through 10 locks to Rivas Vaciamadrid, pulled by draft animals (oxen, horses) on the banks. The canal stopped being used in 1860 when railways took over the job of moving goods overland.

The remains of the Royal Canal timbers found in the Metro excavation are from the first section of the channel. Thick wooden planks lean back at angle in two walls opposite each other 30 feet apart. The section is about 100 feet long, and the wood is in excellent condition, preserved by the watery environment. The wooden walls are accompanied by the remains of the old stone block and brick pier, and numerous bones of the animals used to drag the barges down the canal.

The planks and stakes appear to be made of elm and pine, but archaeologists have taken samples of the wood for analysis to confirm the type of wood and its place of origin. The planks will not remain in situ as a tunnel borer is on the way to obliterate the place and make a subway station out of it. They will be recovered and the best-preserved ones will be put on public display in the new Madrid Rio station when it opens in 2026-7.

The residents of the Arganzuela neighborhood are up in arms about this plan. They had reported the presence of Royal Canal remains in the area two years ago before construction began, and advocated that the Metro station be built in a nearby location instead, which was actually the original plan. The city of Madrid is under fire for having blown off the neighborhood association’s concerns and being so sanguine about boring the historic canal walls to oblivion.