Meet your guide in Praça Afonso de Albuquerque, the open square that fronts Belém's riverside and marks the start of our walk through Portugal's Age of Discovery. At its centre rises a tall neo-Manueline column crowned with a statue of the man it's named for: Afonso de Albuquerque, the admiral who secured Portugal's foothold in the Indian Ocean in the early 1500s and was known, with a mix of dread and admiration, as "the Terrible." Directly across the square sits the Palácio de Belém, the salmon-pink palace that has served as the official residence of Portugal's president since 1911. Once a royal summer retreat, it's where visiting heads of state are still received today. Your guide sets the scene here: why this small riverside parish became the launchpad for voyages that redrew the world map, and what to look for as we move through it.

A few steps on, we pause in the Jardim Vasco da Gama, a pocket of greenery named after the navigator whose voyage to India in 1498 changed the course of Portuguese history. It's a calm spot to gather before the grand monuments ahead, and a good moment for your guide to introduce Vasco da Gama himself — not the statue-on-a-pedestal version, but the ambitious, sometimes ruthless captain whose sea route to the East brought Lisbon extraordinary wealth and set everything you're about to see in motion.

No visit to this neighbourhood is complete without its most famous flavour. Pastéis de Belém has been baking its custard tarts on this exact spot since 1837, and the recipe behind them is one of Lisbon's best-kept secrets. The story goes back to the monks of the nearby Jerónimos Monastery, who sold sweet pastries to survive after Portugal's religious orders were dissolved in 1834. That recipe passed into the hands of the shop next door, where it's still prepared today in a back room known as the Oficina do Segredo — the "secret workshop" — by a handful of pastry chefs sworn to keep it. Your guide explains why the original tart guards the "pastel de Belém" name so fiercely, and what sets it apart from the pastéis de nata you'll find on every other corner.

We arrive at the Jerónimos Monastery, the crowning achievement of Portuguese Manueline architecture and a UNESCO World Heritage Site. Commissioned by King Manuel I around 1501 and built over the course of the 16th century, it was funded in large part by the riches flowing back from the spice trade Vasco da Gama had opened. Every doorway and column is carved with ropes, anchors, sea creatures and knots — stone turned into a celebration of Portugal's seafaring golden age. Your guide walks you through its history and points out the details most visitors miss, from the astonishing south portal to the two-storey cloister often called one of the most beautiful in Europe.

Adjoining the monastery is the church of Santa Maria de Belém, and stepping inside is a quiet, powerful moment. Slender columns rise like palm trees into a single vaulted ceiling — one of the boldest engineering feats of its age, and remarkably, it held firm through the 1755 earthquake that flattened much of Lisbon. Flanking the entrance lie two of the most important tombs in the country: Vasco da Gama on one side, and the poet Luís de Camões, author of the national epic Os Lusíadas, on the other. Explorer and storyteller, resting side by side. Your guide ties the two together, explaining how one man opened the sea route and the other turned it into the myth that still shapes how Portugal sees itself.

Out in front of the monastery stretches Praça do Império, a vast formal garden built around a grand luminous fountain. It was laid out in 1940 for the Exposição do Mundo Português, a sweeping exhibition staged to celebrate Portugal's history and empire, and its clipped hedges and geometric beds still frame the monastery beautifully. Your guide uses the open space to step back and take in the full sweep of the Jerónimos façade, and to explain how this whole riverside was deliberately shaped in the 20th century into a stage for national memory.

On the water's edge stands the Monument to the Discoveries, a towering slab of stone shaped like the prow of a caravel setting out to sea. The version you see was built in 1960 to mark 500 years since the death of Henry the Navigator, who leads the procession of 33 carved figures — kings, explorers, cartographers and missionaries — sculpted along both flanks. Set into the pavement in front is an enormous compass rose and world map, a gift from South Africa, tracing the routes and dates of Portugal's voyages. Your guide reads the monument for you: who each figure is, why they earned their place, and the more complicated legacy behind the triumphant pose.

Our walk ends at the Torre de Belém, the fortified tower that has guarded the mouth of the Tagus for five centuries and become the enduring symbol of the city. Completed around 1519 under Manuel I and designed by Francisco de Arruda, it's Manueline architecture at its most delicate — carved balconies, watchtowers and, tucked beneath one corner, a stone rhinoceros said to be the first of its kind in Western European sculpture. For generations of sailors, this was the last sight of home on the way out and the first on the way back. Standing here, with the river opening toward the Atlantic, your guide brings the day full circle: this is where the voyages you've been hearing about all morning actually began.