the ends of the Earth
The most remote or inaccessible places on Earth; anywhere one needs to go to accomplish something. Baby, my love for you is so strong that I would go to the ends of the Earth to be with you! That no-good cheat robbed me of my inheritance, and I'll follow him to the ends of the Earth to get it back.
ends of the earth, the
The utmost limit, as in She would go to the ends of the earth for him. This usage was once literal (referring to the farthest reaches of the planet) but now is used only figuratively.