Experiments were performed to investigate convection in two types of corners. One, the V corner, is formed by two 45° inclined, upward-facing, heated plates which intersect at 90°. The other, the L corner, is formed by an upward-facing, heated horizontal plate which intersects with a heated vertical plate. In both cases, the two plates had the same uniform temperature which was varied parametrically. The variations of the surface-to-ambient temperature difference and of the plate length yielded a Rayleigh number range from 2 × 106 to 1.5 × 109. Apparatus modifications were also made to investigate the possible role of end effects. The heat transfer experiments were supplemented by flow visualization. The Nusselt numbers for all cases were amenable to power-law correlations with the Rayleigh number. The values of the Nusselt number at the walls of the V corner and at the horizontal wall of the L corner were greater than those for the counterpart single plates.