Visible impression of transition region height. Isosurface of the temperature at log T/[K] = 5.0 and a vertical cut through the domain showing the density above the main magnetic polarities (gray-scale bottom picture). Color code of the isosurface and the plane indicates logarithmic densities. A dense coronal loop is visible in the vertical cut. The domain shown is 50 × 50 × 30 Mm.