Each lung has three major surfaces:

• Costal surface - smooth, curved and convex outer surface; it lies against the internal surface of the rib cage and is covered by the costal pleura; this surface contains rib impressions called costal grooves;
• Diaphragmatic surface - smooth and concave inferior surface that corresponds to the convex domes of the diaphragm;
• Medial surface (sometimes also called the mediastinal surface) - sagittal-oriented surface that faces the mediastinum.

Besides the major surfaces, the lungs also have smaller minor surfaces called interlobar surfaces. The interlobar surfaces are the inner surfaces located within the lung fissures between adjacent lobes.