The Secret of Lisbon Underground is Revealed Twice a Year

Find out what is the secret of Lisbon underground and why everyone endures the long queues to see it.

EDIT: Changes have been made to how you can visit this attraction. Since April 2016, the City Council charges a €1.00 fee per person (approximately USD $1.15) and you must book your visit in advance here.

About twenty years ago, as I was walking aimlessly through the streets of downtown Lisbon, I had a fortuitous encounter with a hole in the ground, in the middle of the street. It was my first visit to the capital and I thought that, for sure, it was destiny opening up a street of Lisbon to a rarely seen attraction. I had been given the chance to visit the secret of Lisbon underground.

Today I know it happens regularly twice a year (I just happened to be here and passing by at the exact right time). Back then there was no such thing as Social Media and the queues were smaller. No way I had to wait for (almost) five hours in line to go underground.

So What does Lisbon Hide Down There?

As we waited (patiently) in line and as we approached the entrance (it still is a hole in the ground on Rua da Prata…), people were coming out showing mixed feelings. However their experience had been like, they still had an amazing sense of humor and were coming up as if they had just been rescued from falling down a well.

In 1771, while rebuilding the city after the great earthquake in 1755, they found what seemed to be a foundation-like structure that could be traced back to the Roman Empire era, estimated to be from the first half of the 1st Century AD.

Once they started building the sewage system in the 18th Century, the access to the whole monument was limited but you can still see the robust structure that, literally, holds part of the Baixa Pombalina up and that, when it was built by the Romans, was meant to level the ground and make it stable enough to hold their constructions.

Find out what is the secret of Lisbon underground and why everyone endures the long queues to see it.

Why Should You Wait In Line For This?

If you like once in a lifetime findings, this is one of them. I confess that seeing it once is more than enough and not much changed — it’s wet and damp, and in most places, you have to mind your head and duck down as much as you can. What would have changed anyway?

The free access surrounds it with a “why not, as long as we’re here” sense. And the knowing that it only opens twice a year for one weekend helps to build up the mysticism around it. As we were waiting in line, many tourists who were passing by approached me asking “what’s down there that people queue to see??”. I did my best to explain the historical importance of it; some of them were curious to come back the next day, some of them were not.

Find out what is the secret of Lisbon underground and why everyone endures the long queues to see it.

I wondered if it’s still worth the trouble to have groups of 25 people each to go down there for 20 minutes guided tours. The dedication of the volunteers to this is, however, inspiring — they don’t get paid to do it, they willingly give up on their free time once a year, and they are willing to share their knowledge. They enjoy talking about its History, its function and how it still endures after all this time.

Any other day these ruins are flooded with the nearby river waters — you can still see the openings (now closed by the pavement) that people used to fill buckets and use the water for cooking and cleaning; after the construction of the sewage system the water was of course no longer safe to drink and the holes were closed.

For us to be able to see this piece of History, there is a collective effort going on: the police reroute traffic (except for the famous tram 28), the fire department pumps the water out a few days in advance and, of course, the volunteers who guide us, in particular, our guide Catarina who briefly (yet passionately) told us the History of the place.

Find out what is the secret of Lisbon underground and why everyone endures the long queues to see it.

Rua da Conceição 77

+351 217 513 200



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