There was an earthquake of magnitude 4.3 on the Richter scale today (17 Aug 2017) at 7.44am, just north-east of Sobral de Monte Agraço, around 35km from Lisbon.
At the moment, news channels are reporting that no-one has been hurt and no damage caused.
Portugal lies on the border of the African and EuroAsian tectonic plates. As they grind across each other, earthquakes are frequent but they are usually small.
The one that devastated Lisbon and other towns in Portugal in 1755 is estimated to have been at least 10,000 times more powerful.
Like Lisbon, much of the western Algarve suffered badly in the ensuing tsunami.