Vang Vieng is at the halfway point on the bus ride from Vientiane to Luang Prabang - about 6-8 hours (road and bus conditions permitting) from Luang Prabang. The ride to Vientiane takes about 4 hours. Some touts say the VIP bus (45k Kip+) takes two hours: this is not true. The VIP bus is just a coach and tends to wait until it is full before departing so take the departure time with a pinch of salt. The alternative is the local bus (set price 20k kip) which can be very crowded or a tuk-tuk (20k kip+). There really is no other way to Vang Vieng.
Vang Vieng is riddled with such an array of guesthouses, restaurants and shops that it's hard to know what to do on arrival. Just about every shopfront on the main streets of this small but rapidly developing town caters exclusively to the tourist dollar. If you're looking for some Lao culture, this isn't the place to find it.
The reason this tourist mecca has sprung up is the gorgeous Nam Song River and the magnificent karst limestone mountains lining it. The imposing structures rise up out of the land and run for kilometres, abutting pancake flat rice fields and the river. Stunning at any hour, the mountains are of course particularly beautiful with the golden pink glow of sunset behind them... the perfect time to sit and have a drink in one of the riverside restaurants.
For action and adventure, there are caves to explore, trekking, kayaking and rafting trips and for the ultra-adventurous, there's rock climbing. To chill out and enjoy the scenery, hire a tyre inner tube and float down the river basking in the beauty of the countryside, stopping for beers along the way.
Vang Vieng is a great place to break the journey between Vientiane and Luang Prabang.