Strömgren volume in a turbulent medium. The columns correspond to different viewing angles: along the y-axis (left), and along the x-axis (right). Top row: density in a planar cut through the centre of the box. The white star indicates the position of the ionizing source. The white contour shows the ionization front, defined as the radius where the neutral fraction rises above 0.5. Middle row: surface density of the neutral gas. Bottom row: surface density of the ionized gas. White patches correspond to sight lines along which all the gas is neutral.