Hang on the rocks
When I walked a little bit futher west of the old town, I saw houses hang on high rock cliffs with balconies overlooking the valley down. They were built in typical for Pyrenees style: made of natural stones and rocks, covered by gable roofs and had wooden balconies.
In contrast to vast valleys I have seen in the Alps, the valley of Andorra la Vella is relatively narrow. Thus there is no much space for the next buildings. The other reason for construction edificies higher and higher is air pollution from traffic down in the bottom of the valley. And the views over the mountains and valley from these hanging high in the rocks houses have to be spectacular.

motorbikes on street
CHURCH OF ST. STEPHEN, ANDORRA LA VELLA
The House of the Valley
Caldea in the background