I visited the Santuario de Chimayo in northern New Mexico several times over the last few decades.
It has always attracted me because of its story. A couple of hundred years ago a priest was martyred at that location and it became a healing and sacred ground.
Hundreds of people visit the tiny adobe church every year and many claim to have been healed from illness or deformity. Some leave their crutches as evidence and others post a note or picture with their story.
The world is filled with sacred places. Lourdes, Medjugorie, Machu Pichu, Sedona vortexes, the Wailing Wall, Stonehenge and Ayres Rock to name a few. Not all of them have a healing component, but all of them have an energy different from the norm; you can feel it if you move yourself into a quiet meditative state.
Why does one place become sacred and not another? I think it has to do with the collective energy we human beings leave there through time and thought.
I think we have far more spiritual power than we remember and we leave that energy in places by our appreciation or awe or reverence of the location or an historical event that took place there.