The climbers tested their balance along the narrow rope walls that lined the training course.

Under the microscope, the plant's cell-walls appeared thick and clearly defined, protecting each cell.

The director instructed the actors to break the fourth-walls at key moments to involve the audience.

During the factory tour we warned visitors to be careful near the hot walls.

During the surgery, the doctors inspected the patient’s chest walls for signs of trauma.

The explorers mapped towering cosmic walls that marked the borders between ancient star empires.

The museum's restoration plan focused on preserving the dead walls that still bore traces of the original frescoes.

Domain walls formed between regions of different magnetization in the thin film.

Many modern offices install living walls to improve air quality and employee well-being.

Many websites use login walls to restrict access to premium articles, frustrating casual readers.