By which civilisation were 'wharenui' built?

Arohanui, I've heard about whare houses but never been inclined to visit one.

On a Marae there is a "meeting house" also sleeping quarters, dining hall and usually a large kitchen. You are "called" onto the Marae by a welcoming party, especially during tangis (funerals) where the loved one is laid out, surrounded by whanau, (family). Awesome send off.