This National park is very difficult to access but apparently very worth to see.
The best way to get there is to go to Miri from Kuching and then take a plane to Gunung Mulu National Park to see the numerous caves and the nature in the jungle.
This is what the place look like:
There, the caves are really awesome. I am thinking to visit the Clear water cave:
It is apparently a tough trip of 6 or 7 hours walking in an underground but it is worth to do it.
The ticket to enter in this national park can is valid during 5 days. It is worth to see the other caves around but also all the biodiversity as this place contains more than 3500 species of plants and loads of animals.
It should be good to take advantage of the ticket and stay at least 3 days there, and also ask if it is possible to do some bivouac in the caves.
The most important thing that I want to do there is the trek called the Pinnacles as these guys did. It consists in climbing up to have the amazing view from the top and see these big rocks coming overhanging the forest.