By public transport: How to get to Konglor Cave from Tha Khaek
You can show up at the 3km market in the morning and find a tuk-tuk going to points along route 8 -- Lak Xao, for instance -- which drop off in Na Hin -- about 40,000 kip. Alternately, you can take any northbound bus from the main bus terminal and ask to get off at Vieng Kham. From there there are hourly departures to Lak Xao, and again, get off at Na Hin.
Once in Na Hin, songthaews to the cave leave when full between 07:00 and 11:00, and one final departure at 14:00 -- about 40km, 30,000 kip. If you arrive too late for the songthaew and want to make it to the cave that evening, the Tourism Office, on the main road 200m east of the eastern turnoff to Na Hin on the right, might be able to arrange a car for US$50 one way, or you can rent a motorbike for US$17 if one is available. But you probably will arrive too late to tour the cave anyway and have to overnight near the cave anyway, so might as well head out in the morning.
By public transport: How to get to Tha Khaek from Konglor Cave
For the return, there are songthaews back to Na Hin at 07:00 and 08:00 -- 30,000 kip. There are no songtheaws after 08:00, so if you arrive in the evening, by the time you tour the cave in the morning, you'll have to stay another night to catch the morning songthaew. If you're desperate to get back to Na Hin, ask at the Auberge Sala Hin Boun about the possibility of private transport -- expect it to be very pricey. You could also try hitching a ride on a Tak Tak (tractor pulling a cart) and have your ass spanked by a wooden board for four hours.
From Na Hin, there are hourly departures to Tha Khaek from 08:00 to 11:00, 45,000 kip, and buses to Vientiane for the same price until 12:30. Buses to Vientiane can drop off passengers at Vieng Kham where you can catch a bus to Tha Khaek until 17:00. If you miss the last bus, there's a place to stay in Vieng Kham, 800m south of the bus station on the right. You can flag down a south-bound bus from here in the morning.
The spectacular Konglor Cave is actually a portion of the Hin Phou river that has worked its way, over some vast period of geological time, through 7.5km of solid rock. It's a truly awesome experience, from which no one ever walks away disappointed.
Bring a good flashlight with fresh batteries, and prepare to get wet -- especially in dry season, there are frequent portages in the cave where you'll have to walk inside the dark cave while the boatman hauls the boat along. Your feet will definitely get wet, so shoes and socks are a mistake. You can easily lose a flip flop in the rushing water, but if that's all you've got, find some string and tie them to your feet -- seriously -- some of the limestone formations are razor sharp and you don't want to wind up inside the cave barefoot. A good pair of sandals are your best bet.
It takes about an hour to get through the cave. The entrance on the other side lets out 3km from Ban Natan, where homestays are available if you'd like to spend the night. But, typically, after a break on the other side, you get back in the boat and do the return. Locals going back and forth between Ban Natan and Ban Konglor routinely do it the same way. The only other option is a strenuous four-hour hike over the mountain -- if you're fit and ambitious enough for it, you'll have to hire a local guide to show you the way.
