  The Monitor project is a large-scale program of photometric and spectroscopic
monitoring of young open clusters using telescopes at ESO and other
observatories. Its primary goal is to detect and characterise new low-mass
eclipsing binaries, and the first three detected systems are discussed here. We
derive the masses and radii of the components of each system directly from the
light and radial velocity curves, and compare them to the predictions of
commonly used theoretical evolutionary models of low-mass stars.
