I visited Warsaw for the first time in September 1980 and made a pilgrimage to the site where the Ghetto had been, including Niska Street, where my mother had lived. Shown here are a few of the many photos I took on that visit. As can be seen, nothing remains of the houses that once stood there, not to mention their inhabitants.
There is a considerable amount of information on the Warsaw Ghetto on the web, including a lengthy entry on Wikipedia (including a map), Warsaw Ghetto Database, and large collection of photographs from inside the ghetto.