In "aizeho mekomon" (the 5th chapter of Maseches Z'vachim)we learn that the the porim hanisrofim were burned in the Beit HaDeshen. What please was the location of the Beit HaDeshen? I seem to remember a mention of "Batei Ungarin". Is there a map on the Web?
A sattelite image of Batei Ungarin can be readily found on Google Maps. I believe the Shomrei Emunim Rebbe (whose chassidim live in that area) had a tradition that it was indeed the Beis HaDeshen.
However, there are some who believe the true location was in the very near Beis Yisrael neighborhood (this is even mentioned in its Wikipedia entry). If memory serves correctly, the biography of R' Yosef Chaim Sonnenfeld (which I do not have access to at the moment) describes how they discovered red, oily soil when they first drained the swampland that was to become the Beis Yisrael neighborhood. Microscopic analysis revealed fragments of animal bones, which made it a quite plausible candidate for the Beis HaDeshen.
See also this sefer (middle of 2nd column), which states that there were two mounds in that vicinity about which there was a tradition connecting them to the place where the Deshen was taken.