The Lower Town at Mohenjondaro provides examples of residential buildings. Many were centred on a courtyard, with rooms on all sides. The courtyard was probably the centre for activities such as cooking and weaving, particularly during hot and dry weather. There were no windows in the walls along the ground level. Besides, the main entrance did not give a direct view of the interior or the courtyard. Every house had its own bathroom paved with bricks, with drains connected through the wall to the street drains. Some houses still have remains of stair cases to reach a second storey or the roof. Many houses had wells, often in a room that could be reached from the outside and perhaps used by passers-by.