Try the Hungarian version, the original name of the place: Erzsébet Tér 3
This is in the center of Pest, 5-th district, and there is a hotel on that spot currently.
If you Google the address as "Budapest Erzsebet Ter 3" you might even get an areal picture of it on GoogleEarth.
If you dig around, you might find out the past of that address.
Leslie from California USA