The imaging and manipulation of matter at the scale of individual atoms has been a long-standing dream that has become reality since the scanning tunneling microscope (STM) was invented by Gerd Binnig and Heinrich Rohrer, who received the Nobel Prize for Physics in 1986 (1). In STM and related scanning probe methods, a probe tip of atomic sharpness is brought within close proximity to the object under investigation until some physical signal can be measured that might originate from electronic, electrical, magnetic, optical, thermal, or other kinds of interactions between tip and sample. Point probing by a sharp tip allows one to receive local information about the physical, chemical, or biological state of a sample, which facilitates the investigation of site-specific sample properties. By scanning the probe tip relative to the sample under investigation by means of piezoelectric drives, a spatially resolved map of the sample in the light of the particular type of selected interaction is obtained. To achieve high spatial resolution the distance s between the probe tip and the sample is chosen to be smaller than the characteristic wavelength λ of the particular type of interaction acting between tip and sample. (In the case of STM, λ would be the electron wavelength, whereas for a scanning optical microscope, λ would be the optical wavelength.) In this so-called near-field regime (where s < λ), the spatial resolution is no longer limited by diffraction but rather by geometrical parameters: the distance s between the probe tip and the sample surface, and the effective radius of curvature R of the probe tip. STM and related scanning probe methods are therefore exceptional types of microscopes because they work without lenses (in contrast to optical and electron microscopes) and achieve “super-resolution” beyond the Abbé limit. For strongly distance-dependent interactions, the dominant tip–sample interaction region can be as small as a few Ångstroms, thereby allowing the imaging of individual atoms and molecules on surfaces (Fig. 1). This new experimental technique has led to several textbook (2) examples of real-space observations of quantum phenomena, such as the interference of electron waves in the vicinity of atomic impurities (Fig. 2), in “quantum corrals” (4), or in low-dimensional solids exhibiting charge density waves (Fig. 3). Further remarkable applications include the observation of micromagnetic structures by magnetic probe microscopy (Fig. 4) or chemical reactions by STM (7).