Maria I of Portugal forced Portugal to cede Olivença and other border towns to Spain. (This cession is not recognized by the present Portuguese government, and the country officially considers those territories still to be Portuguese possessions.) On September 29, 1801 John VI signed the Treaty of Madrid (1801), ceding half of Guyana to France, which became French Guiana. The refusal of the Portuguese government to join the French-sponsored Continental Blockade against Britain culminated in the late 1807 Franco-Spanish invasion of Portugal led by General Junot. The ultimate Napoleonic plan for Portugal was to split it into three sections. The northern parts of Portugal,
Portugal all over modern Portugal and remains of Castro culture. Numerous Roman sites are scattered around present-day Portugal, some urban remains are quite large, like Conímbriga and Mirobriga. The former, beyond being one of the largest Roman settlements in Portugal, is also classified as a National Monument. Conímbriga lies from Coimbra which by its turn was the ancient "Aeminium"). The site also has a museum that displays objects found by archaeologists during their excavations. Several works of engineering, such as baths, temples, bridges, roads, circus, theatres and layman's homes are preserved throughout the country. Coins, some of which coined in Lusitanian