Because of its enchanting natural beauty, Jomblang is the best known of hundreds of caves in the Gunungkidul cave complex networking the karst hills along the southern coastline of Gombong, Central Java all the way to the Sewu Mountain karsts in West Java.
Jomblang Cave was formed thousands of years ago when soil and vegetation collapsed beneath the surface of the earth, creating a sinkhole of approximately 50m wide and up to 80m deep. Over the millennia an incredible underground forest took root, nourished by the so-called “Heavenly Rays,” a daily 3 hour window of sunlight that penetrates the bowels of the cave.
To enter Jomblang, you need to be lowered by rope using a single rope technique (SRT). For those new to abseiling it may sound a little daunting but it’s perfectly safe under the supervision of the experienced guides at the cave and no previous experience is required. Upon arrival, you’ll be provided with coveralls, boots, a helmet, headlamp and an SRT set then your guide will run through a safety briefing and demonstration.
When everyone is comfortable you will begin your decent into the cave. Stepping over the edge is a heart stopping moment, especially for those who have never done this type of activity before. But the adrenaline rush is well worth it because waiting for you at the bottom of the cave is the incredible ancient forest.
Once everyone in the group has descended, guides lead the way through a tunnel that connects Cave Jomblang to another vertical cave called Grubug. It is a relatively easy trek of about 300m and if you’ve timed it right, you‘ll be treated to views of beaming light shining through the ceiling of the dark cave onto stalactites and stalagmites. It’s a truly incredible sight that will have keen photographers in raptures. After around an hour of exploring it’s back to Jomblang for the ascent; aided by 15-20 locals hauling on the rope at the top to bring you back to the surface.
Goa Jomblang is located in Semanu district 50 km southeast of Yogjakarta. The most convenient way to reach Jomblang is by private car from Yogjakarta. Otherwise head to Giwangan bus station in Yogyakarta and catch a bus headed to Wonosari, then swap to a minibus bound for Semanu. From there it’s a further 3km walk or ojek ride to reach the caves. Depending on whether you’re travelling by private car or bus you should allow 2-3 hours for the journey as some parts of the road are in poor condition.
Most people make Jomblang Cave a day trip from Yogjakarta but if you prefer to split your trip over a couple of days, Wonosari 10km away has a decent range of guesthouses and hotels to suit all budgets. Just before Jomblang you can stop into Jetis Wetan village chief’s house to leave your belongings while you’re caving and use the bathroom to clean off afterwards. Be sure to leave a small donation.
For conservation reasons, only around 25 people per day are allowed in the cave so book beforehand or be sure to arrive extra early to get a spot. To see the heavenly rays beaming into the cave, the best time to visit is when the sun is at its highest point between 10am and 12pm). Also bring a change of clothes with you as you will get dirty. The entrance fee to Goa Jomblang is around 450,000Rp per person including lunch.
If you prefer to have everything organised for you, there are plenty of tour companies offering Goa Jomblang day trips.