The Nazis’ Secret Passage in the Heart of Lisbon

In the heart of Lisbon, where the grandeur of Rossio Station rises with its Manueline façade and where thousands of Lisboans hurry by every day, lies an almost forgotten story linking Portugal’s neutrality in World War II to the dangerous game of the warring powers. Few know that behind the walls supporting the station there once existed a secret passage leading directly to the Hotel Avenida Palace — a discreet but vital hub for the spy networks operating in the city.

The Portuguese capital, neutral yet coveted, became one of the busiest centres of European espionage. The British and the Germans fought over every piece of information, every contact, every secret that could tip the balance of the war. Lisbon was then a double capital: on the surface, sunny and diplomatic; underground, shadowy and clandestine. And it was in this duplicity that the hidden passage of Rossio became central.

Historical documents confirm that the Hotel Avenida Palace, inaugurated in 1892 as the Grand International Hotel and renamed in 1893, was designed by the same architect as the station — José Luís Monteiro — and built by the Royal Portuguese Railway Company to serve as support to Rossio Station. Records show that during World War II there was indeed a corridor on the 4th floor of the hotel linking directly to the station platforms, allowing important figures and secret agents to move without police control.

The hotel itself, a symbol of luxury and history, became one of the preferred lodging centres for German spies, according to British observers of the time. The Belle Époque elegance, the refined salons, the discreet entrance… all combined to create an ideal setting for the game of espionage under Portuguese neutrality.

Lisbon, neutral but not devoid of secrets, saw in the Avenida Palace not only a monument of the Belle Époque but also a fervent stage of intrigue. Between elegant salons and discreet corridors, diplomats and agents slipped in quietly, walking the fine line between political neutrality and a clandestine network. The architectural feat itself — the proximity to Rossio Station and the construction of this inner link — became a metaphor for the invisible power of unfolding plots, weaving a tense relation between the visible and the hidden.

Even today, the granite shines under the hurried steps of tourists and Lisboans crossing the station or looking up at the elegant hotel building. Yet for those who know the story, this architectural feat is no longer just historical memory: it is a tunnel erected between the ordinary and the extraordinary, between the capital’s everyday life and the underground world of espionage, reminding us that not everything that seems solid is visible.

Paulo Freitas do AmaralProfessor, historian and author