On your way there is a stop-off at Batu Bungan, a Penan resettlement area where you are invited to buy souvenirs or try your hand at using a blow pipe.
Wind Cave will be the first you come to; there is a smallish walk to the entrance of the cave which is on an upward gradient. Be sure to wear good shoes as it can get quite slippery. This cave is tenuously named Wind Cave because at one point in a cave passage there is a slight breeze. There are some massive cave formations in here and Mulu Parks have lit them in a really atmospheric way but again, all walking is done on boardwalks.
At this point you may be all caved out but fear not, for Clearwater Cave is impressive in its own right. There is a slightly longer walk to the entrance to this cave, in fact the park guides take great relish in informing you that there are 200 steps up to the mouth of the cave. However, there are stop-off points along the way where you can rest. If you've already been to the other caves before Clearwater, you may find the cave itself a bit samey, until you hear the rushing water below. This is the only cave open at Mulu which has an underwater river running through, and it's so long that even after two decades of mapping, they still haven't found the source of the river.
It is likely that you will be a bit hot and bothered after your half-day of traipsing through the caves; lucky then that the river that runs through Clearwater Cave forms a delightfully clear pool at the foot of the cave. You are encouraged to swim here and it is advisable to bring a picnic lunch if you want to stay a bit longer.
Trips leave at 08:45 and 09:15 and take 4-5 hours