Lake Masaya lies within the 6 x 11 km Masaya caldera, whose rim appears on the far side of the lake with Lake Nicaragua in the background. The construction of more than a dozen vents within the caldera has restricted Lake Masaya to an elongated, 2 x 6 km area at the far eastern end of the caldera. The eastern caldera rim rises 200 above the caldera floor, which is only 50 m above sea level.
A broad expanse of youthful lava flows extends across the floor of Nicaragua's Masaya caldera, whose wall forms the arcuate rim in the background. The lava flows originated from the post-caldera cones of Masaya and Nindirí and constrain Lake Masaya against the eastern caldera wall. Recent lava flows have flooded much of the caldera and have overflowed its rim in one location on the NE side. This view from the NW shows Mombacho volcano in the distance.