And voila! Nothing happened! This is because the Display settings below are still set to Ticks. Quickly select Display in the list and choose Geometry from the Type drop down menu. We now have buildings, though their rotation might be a tiny bit off. We'll look into that soon (Fig.20).

Fig. 20
Go back to Shape Instance and adjust Scale and Variation according to your preferences. I'll keep Scale at 100% and set Variation to 25% to vary the landscape a little bit.
Step 2.5: Rotation
Select the Rotation option from the list. As you can see, it's set to Random 3D which explains why practically no building is standing upright. From the drop down menu, choose Random Horizontal to only make the buildings rotate around their Z axis (Fig.21 & Fig.22).

Fig. 21
If you don't wish the buildings to be rotated at all, right-click the Rotation controller in the list and choose Delete.
Step 2.6: Adding More Buildings
All that remains now is to add the rest of the buildings. Fortunately, this is a very simple process. In Particle View, select the box called Event01, right-click it and choose Copy. Then right-click somewhere else in the same window and choose Paste (Fig.23).

Fig. 22
Then hook the new Event to the PF Source (Fig.24 & Fig.25).

Fig. 23

Fig. 24
Now, you only need to change a few parameters to have your new building in place. First go to Birth and set the number of buildings you want. This time I want 750 (Fig.26).
[imf:26]
Then go to Position Object to change the position of the new building so they won't be positioned in the same spots as the previous ones. Scroll down to the bottom of the list and under Uniqueness press the New button to generate a random Seed number (Fig.27).

Fig. 26