From Lisbon the lines radiate around the globe – Africa, South America and Asia – a web of names heavy with history and adventure: Vasco Da Gama, Pedro Alvares Cabral, Magellan. The Tagus estuary is a tongue of the Atlantic, licking the feet of Lisbon’s hills. It laps against the southern flank of the Praca do Comercio which has traditionally been the grande entrance to the city. This huge square was the site of Portugal’s royal palace for four centuries until the revolution of 1910. Framed on three sides three by elegant arcades here we find Lisbon’s oldest cafe, Martinho de Arcada, a favourite with the literati it seems. This is the place to start, so, in cool spring sunshine I relax over a drink and watch the world go by.

The towering triumphal arch on the northern side is the gateway to the city’s commercial hub, the Baixa. The cobbled streets are lined with craft shops, boutiques and cafes, abuzz with musicians and hawkers. A swarthy man sidles up to me selling sunglasses. There’s more besides, hashish he whispers, and whips off his shades to eyeball me earnestly. The best of Moroccan, I am assured. Some time later, I make my excuses and leave.

The filigreed iron tower of Elevador de Santa Justa rises from the regular streets of Baixa. It carries a lift up one hundred feet to the Bairro Alto, giving the walker a welcome break from climbing Lisbon’s steep streets. After the lift, there’s one steep flight of spiral steps leading to a dizzying platform, open to the sky and with a stunning panorama of the city.

The platform floats in tourist photo-heaven and I take the essential shots. A girl stands in my frame, dividing it according to the Golden Mean. Her eyes, obscured behind dark glasses suggest depth, amusement. Still, I can’t be certain; they are shadows, yet a reflection of the life and gaiety of this city. I sense that her iris will glimmer the blue of the globe, that lines of navigation will radiate from the infinite depth of the pupil, like a spider’s web connecting all places and times.

After a beer on the giddy heights of the causeway, I enter the Bairro Alto by the ruined Carmelite church, destroyed in the earthquake of 1755. Human rivers join and divide along winding streets. The famous yellow trams provide a good way of navigating this undulating city, on a rollercoaster ride through swirling streets. I go where they take me, alighting at stops where I can surprise myself and explore. Clinking and clattering through the Bairro Alto, my first voyage deposits me at the Jardim da Estrela, where I take a burger and a glass of wine at a kiosk by the pond. Nearby, the grave of Henry Fielding, eighteenth century English novelist and satirist, came here to die, at the age of forty seven. I’m a bit worried about the burger, to be honest.

Taking a stroll down the grimy thoroughfare of Avenida Infante Santo I arrive at Avenida Da India. This hectic motorway mars much of Lisbon’s coast, forming a barrier between the city and its lifeblood – the riverfront. This is Alcantara, the port area, a bustling, edgy zone, built for passing through. The upper frame of this streetscape is the magnificent Ponte 25 de Abril, modeled on the Golden Gate, stretching across the Tagus like a bridge across the sky.

Further west is Belem, point of departure for Portugal’s great navigators. From the mouth of the Tagus they sailed across the Atlantic and carved a new world. They crowd the carved pedestal of the Monument to the Discoveries: Henry the Navigator, Vasco da Gama, Cabral, the discoverer of Brazil – illuminators of a once darkened globe.

Belem is fronted by a beautiful urban park, overlooked by the Jeronimos Monastery. Dating from 1501 it is the jewel of Portugal’s golden age. Funded through tax on the rich bounty of empire, spices, precious stones and gold, it is a masterpiece of exuberant architecture. The interior of the church of Santa Maria is a serene forest of pillars, drawing the soul upwards in elation. Here we find that most restless of seafarers, Vasco Da Gama who established the sea routes to India and the Orient in the early 16th century.

The Maritime Museum showcases Portuguese shipping through the ages. From ancient barks to the lateen rigged caravels and on to faster, sleeker ships, the story is told in beautifully constructed replicas. 16th Century maps show the world as then known, complementing the world chart at the entrance which encapsulates the awesome scale of the exploration. This is a window to the Portuguese soul, a people with a deep affinity for the sea and a heart hungry for discovery.

I stand at last on the roof of the Tower of Belem, built as a fortress to defend the port in 1515. I can smell the Atlantic here, feel its pull. Buildings ancient and modern crowd the hills and sky to the north. To the east, the great bridge spans the river. Looking south to the Outra Banda, I see the figure of Christ, Cristo Rei, arms outstretched, give His benediction to the city of Lisbon.