In Wosilimo, a 45-minute drive northwest from Wamena, Gua Wikuda is said to be several kilometres long, with an underground river that reaches Danau Anegerak. It's possible to visit the first hundred metres of the cave which has a few stalagmites and stalactites. Ask for the lights to be turned on.
It'll cost you about 35,000Rp to get there on a bemo from Wamena.