From JR Hogan's Malaysia Asia blog:
The Fairy Caves are located about 50 km from Kuching Town and getting here is quite easy considering you take a guide with you. The caves are about 8km to the nearest town called Bau which used to be a gold mining town back in the day. The Fairy Cave is also known as Gua Kapor in Malay.
The trip to the Fairy Caves are quite scenic where you will pass various pepper plantations, local villages and lots of greenery. Make sure you stop at Bau Town to stock up on water and snacks as there is absolutely nothing there at the fairy caves. Also, make your toilet stop at town too as there are no toilets at the caves.
The Fairy Cave seems to have been given a revamp as there are walkways and concrete staircases made for tourists or local who go there. I asked Selvem why the Sarawak Government has not paid any attention to these caves here and even he did not know how to answer me. It is a unique cave within Kuching but is not promoted. Seems like the government made the signboards but never really followed up.
Continue reading (incl. pics) at: Fairy Cave at Kuching, Sarawak Borneo