The site was "discovered" by Bl. Anne Katherine Emmerich (of the Dolorous Passion of the Christ fame) and was physically located about 200 years ago. The house was restored and is a pilgrimage site. Its been visited by both Pope Paul VI and by JPII. The spring located near the house has been credited with healing properties, simiilar to those reported at Lourdes.
There was a new shrine to Our Lady of Ephesus dedicated a few years ago at the Basilica of theNational Shrine of the Immaculate Conception in DC.
It commemorates the unique position of honor given to the Blessed Virgin by all the residents of the area, regardless of their faith.
This image, featured in the oratory, was revealed in a vision to an American lady who went to Mary's House on pilgrimage back in 1959. She commissioned an artist to render the painting according to her vision.
Some say that Our Lady and St. John stayed at Bechwat on their trip to Ephesus but this may be pure speculation. Nonetheless, everyone, even Moslems, consider it Our Lady's mountain.
How wonderful to see this landmark.