The law was approved at a cabinet meeting and is aimed at “preserving the memory of this defensive system, acknowledging its historical interest” during the Peninsular War, the government press release said.

“This decision should have been taken earlier but we embrace it with great pleasure, because it is an added value to the preservation of this important heritage and will help us promote it as a touristic site”, the president of the association for the Lines of Torres Vedras told Lusa News Agency.

The government also announced the creation of a special protection area around each of the buildings.

The Lines of Torres Vedras are a military defence system that dictated the ultimate withdrawal of the Napoleonic army of Portugal, in what became known as the 3rd French invasion - one of the most remarkable episodes of Peninsular War.

In 2014, the Portuguese parliament established October 20 as the National Day of the Lines of Torres.

The Lines of Torres Vedras welcome 10,000 visitors every year.