Walking The Baixa Conspiracy

In the book. Diogo watches the Terreiro do Paço ripple like water from his office window, then sees the Tagus drain. Croft, upstairs on the Rua Nova, sees the same mudflat and the people walking out onto it. Years later Croft sails from the Cais das Colunas (The Letter), and the last chapter opens here, with Diogo crossing the empty square at dawn.

Today. The square is the one the book ends with: arcades on three sides, the river open on the fourth. The equestrian statue of José I stands in the middle (later, unveiled in the 1770s).

Do this. Walk down to the river stairs between the two columns, the Cais das Colunas. Stand on the steps and look back at the square. Then face the water and read the Diogo chapter's drain-and-return passage. The wave came up exactly these steps.

Historical note. Eugénio dos Santos conceived the new square as a monumental entrance to the city through the Cais das Colunas, so you are standing at the front door of his plan.

Try it. Diogo counts 231 paces from the square's southern edge to the mouth of the Rua Augusta. Count yours.

The arch was finished in the 19th century, so Diogo never saw it. But the viewing platform is the best flat-ground view of the grid: the Rua Augusta runs straight north to the Rossio, with the lateral streets in parallel on either side, and the Castle on the hill behind. Look for the cornice line, which is unbroken for the whole length of the street, as Diogo notices in the final chapter.

Practical: Open daily, roughly 10:00–19:00. Viewpoint ticket is a few euros; the street-level view of the arch is free. Skip it if the queue is long. You'll get the grid again from the Castle.

In the book. This is Diogo's last walk. He goes up the Rua Augusta, turns east at the Rua da Prata, walks one block, then north up the Rua dos Correeiros. He knows the foundation depths under every building on it.

Do this. Follow his route exactly. On the Rua dos Correeiros, count four buildings up from the Rua da Prata. In the book, that is the building whose trunks go down eleven metres, two more than its neighbours, because of a void he reported in October 1757.

Why it's on the tour. This is the best place in Lisbon to see what the book means by "the trunks". Beneath a bank headquarters (Rua dos Correeiros 9), a guided visit takes you down through layers of the city's history to the Pombaline level, which includes the wells, drains and wooden piles that hold up the Baixa. Of everything on this tour, it is the nearest you can get to Diogo's survey.

In the book. The Tightening, The Burning and The Baixa, wherever the pile-driving is audible through the shutters.

Practical: Free, but visits are guided (about 45–50 minutes) and booking is recommended or required. Recent listings give Monday to Saturday, with several departures a day. Book ahead through the Fundação Millennium bcp.

In the book. After his meeting with Figueiredo, Croft walks south down the Rua do Ouro and sees a sound building being dismantled stone by stone (The Surcharge). The Rua dos Fanqueiros boundary dispute is the deposition Diogo files at the court (The Court), and the street he is measuring on the last page.

Do this. Walk the Rua do Ouro from north to south, as Croft does. The Rua dos Fanqueiros runs parallel; pick a block and look at the façades the way Croft looks at the dismantled warehouse: what looks sound, and whose decision was it that it come down?

Practical: A caution: the old street pattern does not map neatly onto the grid. Treat the book's old Rua dos Ourives and Rua Nova dos Mercadores as occupying the same general zone as today's Rua do Ouro, Rua da Prata and Rua dos Fanqueiros. They are not the same lines.

In the book. Maia presents the four options in an upstairs room on the Rossio (The Fourth Option). The Secretary's reconstruction office is nearby (The Surcharge). Diogo ends the book standing here. The Estaus Palace is on the north side, "refusing the grid's geometry".

Today. The Teatro Nacional D. Maria II (later) stands on the north side, on the site of the Estaus Palace, which housed the Inquisition. Malagrida's auto-da-fé took place in this square in 1761.

Do this. Stand in the middle and turn slowly. The Rossio is the old city refusing to be a grid: irregular, wide, with the hills closing in on every side except the south. Look back down the Rua Augusta; this is Diogo's last view of it.

Nearby. The little Rua da Betesga leads off the Rossio towards the Praça da Figueira. It is where Beatriz Soares's husband had his premises (The Waiting Room). At the corner of the Rossio and the Rua dos Sapateiros is the Arco do Bandeira, a Pombaline-era arch worth a photo.

In the book. Diogo's family would have been at Mass in the Igreja do Carmo on the morning of the earthquake. Three weeks later, after Maia gives him the survey, he stops in the Largo do Carmo and looks at the roofless nave, "the walls standing, the proportions intact" (The Assignment). In The Ship, Bristow's rooms in the Travessa do Carmo overlook the same ruin, still waiting for its restoration.

Today. The roofless Gothic nave is still open to the sky: repairs began in 1756 and were abandoned in 1834, and the ruin stayed. An archaeological museum occupies the apse and chapels.

Do this. Walk into the nave and stand where the roof used to be. Read the passage in The Assignment where Diogo realises "memory is also evidence".

Nearby. The Rua do Carmo is where the book's court sits in its third premises (The Court). The short Rua Nova do Almada, where Maia's works office is, is also close by.

Practical: Closed Sundays. From May to October it is open 10:00–19:00, and from November 10:00–18:00. Admission about €7 per the museum's own website.

In the book. Teresa stands against the church's south wall in July 1757 and hears Malagrida preach the argument she has already read in his pamphlet (The Sermon). It is a Jesuit church, "which was the point".

Today. One of the earliest Jesuit churches in the world, and one of the few buildings in this part of the city to survive 1755. The plain façade hides a very rich interior. The Chapel of St John the Baptist was built in Rome, blessed by the Pope, taken apart and rebuilt here. Note that "Jesuit" has a very particular weight in this book; the church makes the stakes physical.

Do this. Go in, find a place against a wall, and listen. Teresa notices that Malagrida never shouts.

Practical: The church is free. The attached museum charges a small fee. Check opening times.

Immediately behind São Roque, across the street. A terrace on the eastern edge of the Bairro Alto with the whole Baixa grid below you and the Castle opposite. It is close to what Diogo sees on the evening of 1 November, from higher ground, as the fires "moved toward each other" in the lower city. Today it shows the cleared, ordered ground he spent years surveying.

My inference, not the book's: the "convent on the eastern slope of the Bairro Alto" where the court first sits (The Waiting Room) could plausibly be around here.

In the book. The book opens with the bells: "The Sé first, then São Domingos". The cathedral's bells are the first of forty voices Diogo can tell apart.

Do this. Stand on the Largo da Sé and listen. If the bells are ringing, you are hearing what the book opens with. The cathedral's cloister has an archaeological dig worth a look if you have time.

In the book. Teresa's house is in the Alfama, and the old walls held. When her parish church is lost she goes to São Miguel, where Father Pereira hears confession on Tuesdays (The Confessor). Pereira is arrested at "the Alfama church, on the Rua de São Miguel" in June 1758 (The Burning).

Today. The Alfama survived far better than the Baixa, as the book says. Walk uphill from the Sé into the lanes towards the Largo de São Miguel. You are in the dense, "grown into the hillside" city Teresa lives in: narrow, steep, and entirely unlike the grid.

Do this. Walk Teresa's route in miniature: lanes to the church, then "the longer route along the old wall". Notice how the lane turns and the view suddenly opens over the Baixa. In The Confessor she sees the cleared ground and dust below.

Practical: The church's visiting hours are not something I could confirm. Expect it to be open only part of the day.

A terrace above the Alfama with a view over the rooftops, the Baixa and the Tagus. It's the window Teresa has in the book, looking "over the Alfama rooftops toward the Baixa", where she can see the scaffolding on clear evenings. The book's Santa Luzia church, which "lost its nave to the fires", is an invention. The viewpoint is real.

In the book. Maia, eighty and frail, sits at his desk in the castle and accepts Diogo's four objects into the Torre do Tombo's register (The Deposit). Diogo "rehearsed on the climb from the Alfama" and comes back down by a route that opens above the Baixa, where "the whole grid lay open".

Do this. Go to the castle's ramparts and look south. This is the single best view of the book's central image: the grid, the Praça do Comércio at its foot, the Rua Augusta in its axis, the river. Then walk down through the Alfama as Diogo does.

Finishing. If you walk down through the Mouraria (where Diogo lodges with Costa) to the Rossio, you finish where the book does.

Practical: Confirm prices and hours before you go.

In the book. The Ground: 13 January 1759. Diogo is at a trench in Belém when the Távoras are executed on a scaffold built overnight, "out in the open ground between the highway and the river".

Today. The execution ground is long built over. What survives is a small stone marker in a hidden alley (the Beco do Chão Salgado, "alley of the salted ground"), near the Pastéis de Belém. It marks the Duke of Aveiro's palace, which was razed and the ground salted. It is easy to miss, and it is not a tourist attraction. Go quietly. The inscription speaks of the houses of José Mascarenhas.

In the book. Malagrida was held in the tower's dungeon for over two years. Diogo hears his voice through a grille (The Record), and during the executions the Marquise's confessor is kept "where he can hear it" (The Ground).

Do this. Walk along the riverfront and see the tower from the shore, small on its rock, as Diogo does while he eats his bread. If you go in, find the lower levels.

Practical: Confirm hours; the tower often has timed entry.

In the book. After the attack on the king's carriage on 3 September 1758, Diogo recognises "the road from Ajuda" because he surveyed it. The court lived in a tent palace in Ajuda and Belém (The Morning After).

Today. The Palácio Nacional da Ajuda stands on the hillside where the royal tents were (later; the palace was built afterwards). The Igreja da Memória nearby was built by José I in thanks for surviving the attack. Reaching it takes a short uphill walk from Belém, or a tram.