This is THE portuguese weekly fleamarket called "Feira da Ladra ( the Thieve's Market) - today's sellers are perfectly legal!. It takes place every saturday and tuesday from dawn to dusk since the 12th century .
It is placed in a historic place of the city, surrounded by several very important historic monnuments: the Navy Hospital (the first building built to be a hospital, in 1790s), the Ancient Portuguese Army Warehouse (18th century), the Monastery of S. Vicente de Fora (1147, rebuilt and enlarged in later centuries) and the National Pantheon ( since 1916; 1st it was the Santa Engracia Church) where some of the biggest portuguese celebrities are buried. The fado diva Amália Rodrigues, for ex. is there.
View of the navy hospital (background) and army warehouse (right)
Some, not so old, portuguese traditional azulejos.
You also get a view of the river Tejo.
As you can see, there's much more then antiques and old things. Ther's also african, indian, and other sttuff selling.
Handmade paintings made by portuguese art students and painters. They usually show images of typical streets, windows, details and landscape from Lisboa.