To maintain the beauty of the place and also to ensure the team running the entire operation are able to handle the crowd, only about 25 people are allowed to visit the cave every day.
The Goa Jomblang team are professional and know what they're doing. You pay Rp. 450,000 (about USD 45) per person and that includes safety equipment, boots, helmets, guides to accompany the entire group down, insurance, coffee and tea before the adventure, and a simple lunch afterwards. Bring your own headlamp. The boots and helmets were smelly thus bring your own showercap and socks if you prefer. Socks are also good because in case you can't find boots in your size you can get a bigger size and wear socks to compensate for the extra space. They seem to have many pairs of the bigger sizes - it was hard to find boots that fit my US 5 sized feet.
Since only a limited number of people are allowed to visit the cave each day, do come early. The best time to see the light is from 10-ish to 12 noon, so the tour starts at 10am. Aim to reach Goa Jomblang by 9am. It takes about 1.5 hours to get here from Jogja City and even further if you're staying near Borobudur, so plan your time properly! You can book a tour package online that provides transportation to the caves from Jogja and back, and includes the Rp. 450,000 ticket to visit the cave. We already had a driver so we just made sure we reached the cave by 9am to buy our tickets. You can also drop a WhatsApp message to Pak Cahyo Alkantana (+62 811 117 010), who's managing Goa Jomblang, to make a reservation. But still, try to reach by 9am.
Visiting the caves was a phenomenal experience and I am very happy I got to see something so beautiful. The sunlight was just a single stream when we first saw it at about 11am. Then at about 11.47am when the sun had risen further higher into the sky, the entire cavern filled with light and it was truly magical.
The entire group was lifted manually back up in pairs via a pulley system while harnessed, and I hope the 10 men pulling us had lots of water to drink and rest afterwards.
After our exhilarating morning, we headed back into Jogja city, to Rumah Batik for some more batik shopping.
If you're looking for more things to do around Goa Jomblang, you can check out this blogpost. We decided to rest early tonight as we'd be waking up at the ungodly hour of 3am to see the Borobudur sunrise.