2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/37851Scientific motivations for ultra- and extremely high energy neutrino astronomy are considered. Sources and expected fluxes of EHE/UHE neutrinos are briefly discussed. Operating and planned experiments on astrophysical neutrino detection are reviewed focusing on deep underwater/ice Cherenkov neutrino telescopes.12 pages, 13 figures, uses ifae.cls, Invited talk given at 16th Conference on High Energy Physics (IFAE 2004), Turin, Italy, 14-16 Apr 2004 (to be published in the Proceedings). Conference number C04-04-14-2High Energy Physics - Experimenttext