While many would argue you could enjoy the highlights of Vietnam OR Laos in four weeks, few would be willing to try and cover both in the same stretch of time.
So what to do if you have four weeks and want to do both countries well? We'd say stick to northern Laos and northern Vietnam -- not only will that mean you can travel at a more comfortable pace, it means you get to save the south of each country for another trip.
This is a very busy trip plan and you could easily spend two months doing the same trip without adding any new destinations. In view of this we've made suggestions on the number of days to allow in a place, but please consider those suggestions the absolute bare minimum.
Most nationalities can get a visa on arrival for Laos. For Vietnam, most nationalities need to have arranged their visa beforehand. There is a Vietnamese embassy in Vientiane -- get your visa there. Vietnamese "visa on arrival" is not available at the land crossing specified below -- you must already have a visa in your passport (assuming you need one).
Vientiane: Days 1-2
Kick off your trip in the Lao capital of Vientiane. Allow at least two days to explore the museums, temples and enjoy the riverside sunsets.
Vang Vieng: Days 3-5
We're not a great fan of the Lao tubing mecca, but take away the trashed tourists and what remains is a beautiful hinterland that can be easily explored by bicycle. Allow three days.
Luang Prabang: Days 6-8
The "capital" of northern Laos, today this is undeniably a tourist town, but a strikingly beautiful one with a plethora of cafes, wats, restaurants and surrounding villages worth exploring. Allow at least three days.
Nong Khiaw OR Muang Ngoi: Days 9-10
Take the boat north from Luang Prabang to either of these two riverside hamlets. Of the two, Nong Khiaw is the more comfortable and has the better range of accommodation and eateries. Both are lovely. Allow two days in one or the other.
Muang Khua: Day 11
Jump back on the boat and continue north to Muang Khua. A pretty town in its own right, with a slowly developing backpacker and nascent trekking scene, you could easily spend a few nights here, but in this case, you're just overnighting before getting the morning bus across the border to Dien Bien Phu in Vietnam.
Dien Dien Phu: Days 12-13
You'll need a full day in Dien Bien Phu to take in the primary attractions, so depending on how long the bus from Muang Khua takes, you'll be needing to spend two nights here, before taking a northern-bound bus for Sapa.
Sapa: Days 14-16
Sapa is Northern Vietnam's favourite hill station. Allow at least three days here -- one just to recover from the last few days of travel, another to enjoy the town and immediate surrounds and another to do a bit of walking to one of the outlying centres. When you're ready to move on, grab the night train to the Vietnamese capital of Hanoi.
Hanoi: Days 17-19
Some love it, some hate it. We most definitely love Hanoi and with its excellent range of museums (and food) it deserves at least three days. Be sure not to spend all your time running around. Allow a day just to put your feet up and enjoy Hanoi for what it is.
Ha Long Bay: Days 20-21
Organise a tour from Hanoi to Ha Long Bay. They come in same-day through to three-day flavours and prices vary tremendously. Generally you get what you pay for and regardless of what you do end up getting, the bay is so beautiful it won't really matter. With some planning, you should be able to get back to Hanoi in time for a night train or night bus to Hue. We definitely prefer the train.
Sidetrip Dong Hoi: 1 Day
Break the journey at Dong Hoi and visit the amazing Phong Nha cave system. Allow one day.
Hue: Days 22-25
To bed in Hanoi and wake up in Hue -- how's that for easy travel? You slept a little bit right? Hue is the imperial capital and deserves two to three days, but be wary of spending too much time revisiting the tombs -- they're a bit of a time-sink and not all tombs are equal. Do allow time for eating as the food in Hue is excellent.
Sidetrip Dong Ha: 1 day
Visiting the DMZ is easily done on a full-day tour from Hue or Dong Ha. It can also be visited independently, but a good guide can be worth the extra money.
Savannakhet: Days 26-27
From Hue you're getting the international bus via the border town of Lao Bao to Savannakhet. That means you'll be having dinner and an iced BeerLao on the bank of the Mekong River. Who could possibly complain about that! Savannakhet itself isn't awash in tourist highlights, so take a slow day to work all that travel out of your system.
Tha Khaek: Days 28-30
It's just a few hours north by bus to Tha Khaek, the capital of Khammuan province and the popular hub for the Tha Khaek Loop. If you're able to ride a motorbike or scooter, allow at least two full days to explore the region, including the fabulous Konglor cave. You could easily allow one more day to enjoy the slow pace of life and pretty scenery before heading back to Tha Khaek for that long, last bus ride back to Vientiane.
If that's way too much time on four wheels, skip Muang Khua and Dien Bien and fly from Luang Prabang to Hanoi (visit Sapa by overnight train both ways from the capital).
If you don't plan to return to Vientiane, you could easily continue south into southern Laos (and even Cambodia) from Savannakhet. This trip plan for southern Laos makes some useful suggestions if you're headed that direction.
Likewise if you wanted to continue into southern Vietnam, this Southern Vietnam itinerary may be helpful.
Another option for those with more time on their hands is to better explore northern Vietnam and this itinerary for the Dien Bien Phu Loop is informative.
All too complicated?
Another option would be to consider doing an organised trip through the area. One advantage for some would be that you may be on a private minibus rather than local transportation (though we like to think that's half the fun). Reputable operators include All Points East or Intrepid.
Where to go, how long to stay there, where to go next, east or west, north or south? How long have you got? How long do you need? Itinerary planning can be almost as maddening as it is fun and here are some outlines to help you get started. Remember, don't over plan!
Burma lends itself to a short fast trip with frequent flights thrown in or a longer, slower trip where you don't leave the ground. There isn't much of a middle ground. Ground transport remains relatively slow, so be wary about trying to fit too much in.
Roughly apple-shaped, you'd think Cambodia would be ideal for circular routes, but the road network isn't really laid out that way. This means you'll most likely find yourself through some towns more than once, so work them into your plans.
How long have you got? That's not long enough. Really. You'd need a few lifetimes to do this sprawling archipelago justice. Be wary of trying to cover too much ground - the going in Indonesia can be slow.
North or south or both? Laos is relatively small and transport is getting better and better. Those visiting multiple countries can pass through here a few times making for some interesting trips.
The peninsula is easy, with affordable buses, trains and planes and relatively short distances. Sabah and Sarawak are also relatively easy to get around.The vast majority of visitors stick to the peninsula but Borneo is well worth the time and money to reach.
So much to see, so much to do. Thailand boasts some of the better public transport in the region so getting around can be fast and affordable. If time is limited, stick to one part of the country.
Long and thin, Vietnam looks straightforward, but the going is slow and the distances getting from A to B can really bite into a tight trip plan. If you're not on an open-ended trip, plan carefully.
This is where itinerary planning really becomes fun. Be sure to check up on our visa, border crossing and visa sections to make sure you're not trying to do the impossible. Also, remember you're planning a holiday -- not a military expedition.