A man wanted for questioning over 16 fires started in the countryside between Benagil and Marinha is still at large.
The main fire destroyed everything combustible in a valley which leads to Benagil beach (pictured).
Vegetation was destroyed, as were wooden barriers protecting viewers from falling down blowholes.
A house almost was consumed by flames and the fire was found to have been started at various points causing maximum difficulty for the Lagoa fire service in difficult terrain.
Juniper bushes, stone pines and dwarf palms are among other species reduced to ashes and will take years to recover.
The suspect, a 40-year-old man with a criminal record and mental disorders, also tried to set fire to a nearby pine forest at Benagil. He managed to start 16 fires in one night, all of which were put out by alert firefighters.
The next day, the arsonist set two more fires in the same area and the day after, he lit another.
As for the vegetation, the mayor said he is looking at "a replanting plan, perhaps with the help of scouts, but this can only be done after some rain."
The arsonist, who lives in the area, was spotted by witnesses on the first night. Since then he has not been seen but is thought to be hiding in the Benagil area.
The Judicial Police and the GNR are keen to catch him before someone dies as a result of his crazed activities.