Fire destroyed a third of the houses in Delft.

The great fire in 1536, probably caused by lightening, in turn caused the people of Delft to re-build their city with stone instead of wood. It also meant that few current buildings pre-date the fire. Much of medieval Delft was lost, including Leeuwenhoek's Hippolytusbuurt neighborhood between the Stadhuis and the Oude Kerk. Both of them, built of stone, survived the fire. The city archives stored in the Stadhuis did not survive, however, which is why the timeline of events is so sparse before then.

The gates stick out into the singel more than in reality. At either end of the Oude Delft gracht, the double gates of Rotterdamse/Schiedam and Haag/Wateringse are not clear. At the top, the Waterslootse Poort doesn't have its bulwark yet. The four windmills in the top corner are all aimed toward the winds coming off the North Sea. Along the bottom, the Duyvel's Gat looks as though it gives water access, and the Koepoort looks as though it doesn't. In the bottom left corner (southeast corner of the city), Leeuwenhoek's boyhood neighborhood lay untouched.