The main objective of this proposal is to investigate the dynamics of ultra-confined water in the slits pores of geological cavities (mineral tobermorite). This system provides an excellent model to analyze the dynamical properties of water confined in cement-like materials, which are much more complex than tobermorite due to their different pore sizes. Furthermore, the severe confinement of tobermorite will prevent crystallization of the water at any temperature and make it possible for us to combine the present QENS study with broadband dielectric spectroscopy (BDS), covering the frequency range 10-2 - 109 Hz and therefore also a broad temperature range. The main aim of this study is to compare the water dynamics in natural and synthetic tobermorite and to determine the physical nature of the relaxation processes observed by BDS.