Had the Richter Scale been invented then, the great earthquake which all but destroyed Lisbon on 1 November 1755 (All Saints Day) would have registered a massive 8.9.
The first of the three shocks was at 9.40 am and lasted between 6 and 7 minutes.
An estimated 40,000 people died during the quake, which was felt as far away as Scotland and Norway.

Lisbon’s amazing recovery after the great earthquake in 1755 is largely due to one man, the Marquês de Pombal (1699-1782), who as prime minister directed the rebuilding of the city.
His simple architectural design (now known as Pombaline) can be seen in the parallel streets of the Baixa district and along Avenida da Liberdade, which leads all the way up to his statue at Praça Marquês de Pombal.

Beneath the streets of Lisbon’s downtown shopping area exists a hidden underworld of Roman corridors, bridges, rooms and galleries, which was only discovered after the great earthquake in 1755.
The entrance to this fascinating subterranean district is marked by a block of metal at the top of Rua da Conceição, which is only open to the public two days a year due to the dangerous conditions below.

The great limestone ridge of the Serra da Arrábida, visible from Lisbon 40 km to the south, is home to the world’s oldest living examples of Mediterranean vegetation.
The Arrábida Natural Park (now a protected area) is unique for its unusual soil and microclimate, both rare in this part of Europe.
More than 1,000 species of plant have been recorded there.

Throughout the night of 7 July 1497, the pioneering Portuguese navigator Vasco da Gama prayed in an old mariners chapel in Belém, west Lisbon, for the safe return of his captains and crew from their forthcoming voyage to India.
The expedition was a success and a new sea-route to the East was discovered.
After his return two years later, the chapel was replaced by the imposing Jerónimos Monastery, where his body now rests.

Less than twenty people died in the so-called ‘red carnation revolution’, which ended Portugal’s oppressive dictatorship on 25 April 1974.
The rebellion was triggered by the public broadcasting of a popular old song entitled Grândola Vila Morena, before soldiers of the newly-formed Armed Forces Movement took control with red carnations in the barrels of their rifles.

The world’s earliest recorded balloon was a hot air model invented by Father Bartolomeu de Gusmão (né Lourenço), which was flown indoors at the Casa da India, Terreiro do Paço (better known as Praça do Comércio) in Lisbon on 8 August, 1709.
He later ran away to Spain for fear of being accused of performing black magic by the Inquisition.

The tallest of the Águas Livres Aqueduct’s 14 arches spanning the Alcântara Valley stands 65 metres (213 feet) high and is the tallest of any ancient structure in the world.
The aqueduct, which was built in the 18th century, has 109 arches in all and stretches 19 kilometres (11 miles) from Caneças to the Casa de Agua reservoir in Lisbon’s Amoreiras district.

Apart from its seafaring tradition, Lisbon was also the scene of two record-breaking moments in aviation history.
In 1922, two local pilots, Gago Coutinho and Sacadura Cabral, left the Portuguese capital for Rio de Janeiro in a seaplane called Santa Cruz, to complete the first crossing of the South Atlantic.
Coincidentally, the first North Atlantic flight landed in Lisbon three years earlier on 27 May 1919.

The 25 April Bridge, renamed after the 1974 revolution, is not only Europe’s second-longest suspension bridge but the third longest in the world.
Stretching 1,013 metres (3,323 feet), the bridge opened on 6 August 1966 at a cost of US$45 million.
One of its foundations, with a depth of 79 metres (260 feet) beneath the Tagus river bed, is the deepest of any bridge in the world.

The main river basin of the Tagus estuary in Lisbon stretches 9 miles (14 km) across and is large enough to contain all the warships in the world.
At the height of the Portuguese Empire in the mid-16th century, well over 1,000 river craft were recorded moving between the city’s various ports.
The Tagus River rises in the mountains north-east of Spain and flows 525 miles (840 km) to Lisbon.