Hydrophobic hydration is the concept derived in the 1950s from thermodynamic studies from which it became clear that, in addition to hydrogen bonding, water has some extra ability to bind, without hydrophilic interactions, molecular species which are routinely considered hydrophobic. The outcome, e.g. in the form of stable compounds of water and hydrocarbons, is impressive. This binding is based upon structure effects, namely on aggregation of water molecules around a ‘structure-directing agent’ (as named by silica chemists) or ‘template’ (commonly used by organic synthetic chemists) or, simply, guest component. This is a typical collective phenomenon, not easily corresponding to the classical tools of chemists who prefer to rationalize interactions in terms of bonds between specified atoms. Hydrate solids are often non-stoichiometric, phenomenon which is certainly unknown in molecular chemistry while rather common in solid state sciences. Hydrophobic hydration is a common phenomenon and is important from different viewpoints. Directly as a source of special type of material which may be of practical importance. Indirectly as a means of facilitating synthesis of organic and/or inorganic substances either in nature (as illustrated by the example of porous silica materials) or in the laboratory. Ecological aspects of hydrophobic hydration are manifold. Climate change due to stabilization /destabilization of huge deposits of natural gas in the form of ‘soft’ hydrate material seem the most important on large time scale whilst geohazards and resource of energy are important also on the short time scale. Common occurrence of hydrophobic hydrates on earth is a firm basis for further research of these complex systems, so important for biological life on our planet.