In the following September I went with a small party up the right-hand branch of the river, the Madalam, to endeavour to reach the lofty mountain of Molu, and found that one of the stories told by the natives had some foundation. We followed the Madalam till we reached the Trunan on the eighth day, up which we pushed, thinking it led to the base of the highest peak of Molu. We soon came upon limestone rock, and after a few miles were suddenly stopped by the river, I may say, disappearing. We found a rocky eminence before us, its sharp angles concealed by ferns and climbing plants falling in festoons around, and a luxuriant vegetation of trees, whose bark was coated with mosses, orchids, and other epiphytal plants. There was an arched cavern into which we pushed our boats; at first we failed to find the inlet through which the stream entered, but at last, looking down into the clear water, we saw two huge holes below--the passages from whence the river came. We went round to the southern side of the rock, and there we found the river coming purling along to this lofty wood-crowned mass of limestone, and then entering a spacious hall it was lost, descending, as it were, to the passages before mentioned. There were various chambers with water floors, to the surface of which fine fish occasionally arose. This place is called Batu Rikan. [Illustration: T. Picken, lith. Published by Smith, Elder & C^o. 65, Cornhill, London. Day & Son, Lith^{rs}. to the Queen. THE TRUNAN ISSUING FROM BATU BARIT MOUNTAIN.] We stayed here a night, during which it rained heavily, making the stream that yesterday but washed our ancles, swell so that it was impossible to cross it. We therefore kept along the right bank, till we reached the spot where the whole river issued from the face of the precipice; it was a fine sight, this body of water running impetuously from this natural tunnel. On either side lofty trees arose, and above the precipice the green verdure spread in masses. Our Bisayan guide, the Orang Kaya Panglima Prang, of the village of Blimbing, told us that during fine weather, we could penetrate a long distance under the mountain, though few had ever ventured to do so, on account of the very sudden way in which the water rises. Finding we could not cross the stream near the mountain, we skirted the precipice, which the Bisayas told us it was impossible to climb; but I determined on making the attempt, not crediting the truth of one of their objections that we should find no water on the mountain after the heavy rain which fell the previous night.