There are many remarkable caves in the Philippines. I translate a description of one in the province of Tondo. Two stony mountains unite, and on their skirt is the road towards a branch of the main river. On the left is a cave whose entrance fronts the south. The mouth is almost covered with tangling vegetation, but it is arched, and, being all of marble, is, particularly in the sunshine, strikingly beautiful. You enter by a high, smooth, natural wall like the façade of a church, over which is a cavity roofed as a chapel. The interior pathway is flat, about four yards in breadth and six in height, though in some places it is much loftier. The roof presents a multitude of graceful figures, resembling pendent pineapples, which are formed by the constant filtration and petrifaction of the water. Some are nearly two yards in length, and seem sculptured into regular grooves; others are in the shape of pyramids whose bases are against the roof. Arches, which may be passed both from above and below, are among these wonderful works. Not far from the door is a natural staircase, mounting which you enter a large chamber, on whose right hand is another road, which, being followed, conducts to a second staircase, which opens on the principal communication. Suspended on one wing are immense numbers of bats, who occupy the recesses of the ceiling. Though there is mud in some of the paths, the ground is generally of stone, which, on being struck, gives a hollow sound as if there were passages below. Penetrating the cave for above 200 yards, a loud noise is perceived coming from a clear bright river, by the side of which the cave is continued under a semicircular roof. The great cave has many smaller vaults and projections of a grotesque and Gothic character. The course of the stream is from the north-west to the south-east.
The destructive ravages and changes produced by earthquakes are nowhere more remarkable than in the Philippines. They have overturned mountains, they have filled up valleys, they have desolated extensive plains; they have opened passages for the sea into the interior, and from the lakes into the sea There are many traditional stories of these territorial revolutions, but of late disasters the records are trustworthy. That of 1796 was sadly calamitous. In 1824 many churches in Manila were destroyed, together with the principal bridge, the barracks, great numbers of private houses; and a chasm opened of nearly four miles in length. The inhabitants all fled into the fields, and the six vessels in the port were wrecked. The number of victims was never ascertained. In 1828, during another earthquake, the vibration of the lamps was found to describe an arch of four and a half feet; the huge corner-stones of the principal gate of the city were displaced; the great bells were set ringing. It lasted between two and three minutes, rent the walls of several churches and other buildings, but was not accompanied by subterranean noises, as is usually the case.