List three types of blood cells and what each blood cell does

Red blood cells (erythrocytes)  - Basically they carry oxygen

White blood cells (leukocytes)  - They are the cells of the immune system that are involved in protecting the body against infectious diseases and foreign invaders.

Platelets (thrombocytes) - They help your body form clots to stop bleeding. They form a plug, clot or repair the damage.

explanation:

it's the camino de santiago pilgrimage trail to santiago de compostela in spain, the location of the alleged tomb of the apostle st james. the track has been walked by pilgrims for over 1,000 years. the one you're referring to is the camino frances, which is around 800kms long, and these days more than 100,000 people walk all or part of it annually. most people still walk for religious, or more often, spiritual reasons, a few just because it's there.