Tenement Museum

According to Wikipedia, a  "tenement is, in most English-speaking areas, a substandard multi-family dwelling in the urban core, usually old and occupied by the poor.  In New York City tenements were first built in the 1840's to accommodate mostly poor immigrants.  Many, many tenements existed on the lower eastside of Manhattan.  This is where my grandfather lived from when he was born until his early teens. 
About 25 years ago on Orchard St, a tenement that had been sealed for about 50 years was discovered. This building which had been unoccupied and essentially untouched for many years became the basis for the Tenement Museum.   https://www.tenement.org/  In this building there are 22 apartments and over the year over 7000 people lived there.  We very much enjoyed the tour and learning about life in a tenement such as this where until the early 20th century there was no running water, no indoor toilets and coal heat.