The tower that watched Portugal leave

Belém Tower was built in the early sixteenth century to guard the mouth of the Tagus, and it did the job for less than a hundred years before artillery made it obsolete as a defence. What it has done for the five centuries since is stand, more or less exactly where it was built, as the last piece of Lisbon that departing ships would have seen and the first that returning ones would sight again, for a period when Portuguese ships were redrawing what the rest of Europe understood the world to look like.

That is a large claim for a small country to make, and it happens to be true. For roughly a century from the early 1400s, Portuguese navigators, working outward from exactly this stretch of river, mapped the coast of West Africa, rounded the Cape of Good Hope, reached India by sea and crossed the Atlantic to Brazil, opening trade routes that reshaped the balance of European power. Vasco da Gama is said to have prayed at a chapel on this site the night before he sailed for India in 1497; the monastery that replaced it, Jerónimos, was funded in part by the spice trade his voyage helped establish.

A tower for ceremony as much as defence

Belém Tower itself, finished in the 1520s, is more ornamented than a purely functional fortress needed to be, its stonework carved with maritime motifs and the twisted rope pattern, the Manueline style, that Portugal developed almost uniquely for this one architecturally confident stretch of its history. It sits a short walk from Jerónimos Monastery, another Manueline masterpiece built on profits from the same voyages, and together the two buildings form a UNESCO World Heritage Site that tells the same story from two angles: the ships going out, and the wealth that came back.

A monument built five centuries later

Just along the riverbank stands a very different kind of memorial. The Padrão dos Descobrimentos, the Monument to the Discoveries, was built in 1960 to mark the five-hundredth anniversary of the death of Henry the Navigator, the prince credited with sponsoring much of the early exploration, and it takes the form of a stone ship's prow crowded with the carved figures of the navigators, monarchs and cartographers who made the era possible. It is unmistakably a twentieth-century structure, built under a regime keen to associate itself with an earlier age of national confidence, and it is worth seeing precisely for that layering: a monument to the 1500s, raised in the 1960s, still standing in the twenty-first century.

What came after, and what remains

The age of discovery did not last. By the eighteenth century, Portuguese fortunes rested more on Brazilian gold than on new maps, and in 1755 a catastrophic earthquake, followed by fires and a tsunami, destroyed much of Lisbon, sparing Belém, on firmer ground outside the city centre, almost entirely. The Marquês de Pombal's reconstruction of the ruined city centre in a strict, quake-resistant grid is its own story, visible today in the Baixa district a short walk upriver from the tower that watched the earlier, more expansive version of Portugal come and go.

For visitors arriving by cruise, Belém is usually one call among several on a longer Iberian itinerary, close enough to the ship's berth in Lisbon for a half-day visit that takes in the tower, the monastery and the monument without needing transport. Those who want longer in the city and along this coast can add Sintra and Cascais on a dedicated tour, following the Tagus out to where it meets the open Atlantic that Portuguese ships once treated as merely the beginning of the journey.

Little of the country's former reach remains today beyond the language spoken across parts of four continents and the stone carving on a tower built to see ships off. Both have outlasted the empire by rather longer than the empire itself lasted.