The Giant Radio Array for Neutrino Detection (GRAND) aims to answer one of the most pressing open questions in astrophysics: what is the origin of ultra-high-energy cosmic rays (UHECRs)?
It will do so indirectly: UHECRs make secondary UHE neutrinos which encode information about the properties of UHECRs and their sources. GRAND is designed to discover UHE neutrinos even under pessimistic predictions of their flux, reaching a sensitivity of 1.5 x 10^-10 GeV.cm^-2.s^-1.sr^-1 around 10^9 GeV. It will do so by using 200 000 radio antennas covering an area of 200 000 km², making it the largest air-shower detector ever built. With this sensitivity, GRAND will discover cosmogenic neutrinos in 3 years of operation, even in disfavorable scenarios. Because of its sub-degree angular resolution, GRAND will also search for point sources of UHE neutrinos, both steady and transient.
Moreover, GRAND will be a valuable instrument for astronomy and cosmology, allowing for the discovery and follow-up of large numbers of radio transients - fast radio bursts, giant radio pulses - and studies of the epoch of reionization.
In this contribution we will present the science goals, detection strategy, preliminary design, performance goals, construction plans and current status of the GRAND project.