The main difficulty in understanding the thermodynamics of metal-water interfaces lies in the inherent complexity and heterogeneity at the sub-nanometer scale, which poses severe challenges to computational, theoretical, and experimental approaches. Although it is possible to directly measure interfacial thermodynamic quantities such as the surface tension and the contact angle, the solvation energies of metals have not been reported due to the difficulty of preparing smooth defect-and impurity-free surfaces. The experimentally measured quantities strongly depend on the sample quality and are available only for a handful of metal surfaces. While the low-temperature adsorption of water on metal surface is well-characterized, the values of surface tension, work of adhesion, and contact angle measured at room temperature are scattered and even contradictory. For instance, water contact angle measurements for the same material indicate either complete wetting (contact angle is zero) and strong hydrophilicity or a partial wetting and hydrophobicity. Although most studies seem to agree that water completely wets metal surfaces and that the contact angle is zero at room temperature, this only sets the lower limit for the work of adhesion that can be estimated from contact angle measurements. In particular, the Young--Dupré equation that relates the work of adhesion (W ad ) and the liquid-vacuum surface tension (γ lv ) to the contact angle shows that the angle zero is reached when W ad exceeds twice the γ lv . Hence, the exper-imental value of 4.54 meV/Å 2 for the water-vacuum surface tension means that one cannot use contact angle measurements to extract thermodynamic quantities such as work of adhesion, metal-water surface tension, or the free energy of formation, for interfaces that interact strongly with water, i.e., when W ad > 9.1 meV/Å 2 . Only the recent meniscus measurements have successfully measured the absolute surface tensions and works of adhesion for Pt, Au, and Ag interfaces with water, showing that these surfaces are hydrophilic. However, even the meniscus experiments were performed with macroscopic samples containing multiple surface orientations and possibly defects. The absence of pristine single-crystal experiments is the main obstacle to quantitatively match the experimental findings to the atomic-scale surface structures.