“Eating pasta and sightseeing are two of my favorite activities to do when I visit Italy” Is this a gerund or participial?

a myth is something that is told for many years that u go looking for and cant find and a truth is something that u can find in real life and can be story's of for example:

mermaid's and unicorns: u can't find them at all so they can be a myth cause u hear story's about them once u go looking for them u won't find them.

dinassours(can't spell): u hear story's about them at school by ur friends and one day ur dad takes u to a museum and u find fossils of them so u realize they are real and not fake.

"the sandy walls seemed to collapse in on themselves"

and

"the bloodshot waters seemed to have no bottom"

who is marty in this situation?