How does the sidebar “Unlocking the Secrets of Pompeii” contribute to the article?

The details about the statues, i believe, are that they're carved from blocks of igneous stone, many of them are partially buried under the ground which to preserve and protect them from the harsh environment on easter island, and many of the facial features have washed away. also, the most well-preserved one is at the british museum in london.these are just guesses from what i can see and what i think i read correctly. i'm sorry i couldn't be more .

Walked would be the participle here. as it is a verb ending in -ed.