The destination of the expedition was again Negros (Oriental) in the Philippines. After the first expedition in 1989 a member of the first expeditionteam started gathering people together for a next visite to Negros. It took some time to get a complete team together because at the same time there were also preparations for an expedition to Irian Jaya. During the first Belgian-Dutch Expedition in 1989 mainly the Mabinay area was explored. Because of our good contacts with DENR (Department Environment and Natural Resources) we got permission to explore in the Guihulngan area in the northern parts of Negros Oriental. The area was since 1991 opening up for foreigners. In 1989 the first expedition did not get a permit to explore here. Basecamp was set up at the second floor of the office of DENR in Guihulngan. Guihulngan is a municipality with 23 barangays. The expedition explored in the barangay’s Kinayan, Imelda, Tac-Pao, Bino-Bohan and Sandayao. In the mountains the expedition also set up two subcamps in the sitio’s (villages) Nalundan (Tac-Pao) and in Lip-o (Imelda). Under supervision of the military the expeditionteam got permission to explore the mountains. The mountains and karsthills are 500 to 700 meters high. Entrance to the mountain area is from a road in Bolado. From Bolado it is 8 kilometer uphill to the sitio of Nalundan. Between Bolado and Nalundan there was frequent motortransportation. The expeditionteam was split up in 3 groups. One group explored the Lip-o area, the second group explored the area around Nalundan and the third group was working In Guihulngan. The teams worked in shifts. Every time when a group in the mountains obtained to much information (5-6 days) the team came to Guihulgan to write everything down and make a map of the explored cave in the computer. Then the team who was in Guihulngan went to the mountains en so on.
Standing left Jef Lemaire, Frank Thijssen, Volkert Schaap, Wim van Vliet, René Prévot, sitting left Marianne Lemaire, Jolanda Spronck, Bram de Bree, Maurice Penders, Harold van Ingen, Herman Frederiks, Roger Thijssen and Peter Goossens
During six weeks the expeditionteam mapped 11 caves with a total length of more than 9 kilometer. Three caves are longer than 1 kilometer (Mag- Aso Cave, Small Mag-Aso Cave and Lag-Asan Cave).Small Mag-Aso is now the second deepest cave op the Philippines (denivellation 116 m, - 63/+53m) after the Sumaging-Latipan-Cristal System (denivellation more than 200 meter)
Small Mag-Aso Cave System:
This cave was our main project during the hole expedition. The cave measures 3498 meters (+53, -63) and has a downstream en upstream part. The two parts are connected through a siphon. In the downstream part there is a big chamber, “Cathedral Hall” measuring more than 65 x 25 meters.The system is mostly one rivercorridor with cascades and with an overflow for the rainy season, “Bypass Junction” when the system fills up with water. In the upstream part near “Smokey Campfire” we expect another entrance.
Mag-Aso Cave System:
This was one of our first caves we visited. It has mainly one corridor with a river with several inlets of water. The water flows down from Nalumpan Entrance to a siphon 50 meters from the second entrance pitch (P35). On the other side of Nalumpan Entrance there is another small cave (the locals call it Nalumpan Cave). This cave is also part of Mag-Aso. In the rainy season it wil fill compleetly with water. All together Mag-Aso is 1502 meters long (+5, -39m). The most beautifull part of the cave is the passage behind Shrimp Cascade.
This cave is similar with the other two caves. One corridor with a stream with a siphon after more than 1065 meters (-95m). In the cave are two chamber and several cascades.
List of mapped caves in order of length:
Small Mag-Aso 3498 m (+116 m), Mag-Aso Cave 1502 m (-40 m), Lag-Asan Cave 1065 m (- 95 m), Mainit Cave 850 m (-37 m), Natiniti-An 1 Cave 772 m (+23 m), Gripo Cave 368 m (-104 m), Guano Cave 330 m (-45 m), Natiniti-An 2 Cave 250 m (-6 m), Tacoy Bito 167 m (-36 m), Basketball Bito 134 m (-25 m), and Bino–Bohan Cave 82 m (-4 m).