The desert floor below, backed by mountains that ring the valley, spreads far into the distance. The wall faces northeast and southwest. A viewer is positioned as if to split the difference ...

The valley is located in AlUla, a craggy desert region long known for its Petra-like rock tombs and more recently for its Desert X AlUla contemporary-art biennial.

Zahrah Alghamdi’s work is a natural fit for an outdoor art show ... and architecture. For Desert X, she constructed a massive, squishy-looking wall of stacked squares, each filled with various ...