Thailand Cambodia Vietnam 21 Days Itinerary & Travel Planning Guide

Exploring Thailand, Cambodia, and Vietnam in 21 days is one of the best ways to see Southeast Asia’s highlights in one trip. With one week in each country, you can enjoy a mix of culture, history, and relaxation — from Bangkok’s golden temples and Angkor Wat’s ancient ruins to Vietnam’s peaceful beaches and lively cities.

Traveling between these countries is easy and quick, with short flights or overland routes connecting major destinations. You’ll have enough time to explore local life, enjoy delicious food, and still slow down to take in the scenery. Whether you love adventure, culture, or beaches, there’s a perfect route for you.

This Thailand Cambodia Vietnam 21 days itinerary guide shares four sample routes, travel tips, and ideas for customization. It’s designed to help you plan your own smooth, meaningful, and unforgettable Indochina journey.

Is 21 Days Enough for a Thailand, Cambodia, and Vietnam Tour?

Yes, 21 days are enough for a Thailand, Cambodia, and Vietnam tour. A Thailand Cambodia Vietnam tour itinerary for 3 weeks covers the main attractions most travelers want to see: Bangkok's temples, Chiang Mai's mountains, Angkor Wat's ancient relics, Phnom Penh's complex history, Hanoi's energy, Halong Bay's limestone islands, Hoi An's lantern-lit streets, and Ho Chi Minh City's bustling markets.

The countries are set up for overland travel. You can travel from Thailand to Cambodia and Vietnam by bus or fly in an hour. Cambodia to Vietnam works the same way. If you plan carefully, 21 days give you a good balance of sightseeing and downtime. With roughly one week per country, you can hit key cities and landmarks without feeling too rushed. Travel between these places is relatively smooth.

The itinerary map for 4 21-day trips through Thailand, Vietnam, and Cambodia.

Route 1: Classic Highlights - Iconic Cities and Landmarks

Have a week each in Bangkok and Chiang Mai during your first 21 days trip to Thailand. Explore the golden temples of Bangkok, floating markets, and popular street food and then head towards the north. The serene atmosphere of Chiang Mai, the scenic mountainous, and the cozy night markets will definitely recharge your energy.

Spend the next five days in Cambodia. Start with the awe-inspiring temples around Siem Reap, including Angkor Wat tour, then continue to Phnom Penh for riverside strolls and a deeper look at the nation’s history. The contrast between Cambodia's ancient wonders and modern recovery adds real depth to the journey.

End with nine days in Vietnam. Explore the heritage and tastes of Hanoi Old Quarter, take a cruise at Halong Bay, and head down south to Hue and Hoi An for historic sites and beach relaxation. End up in Ho Chi Minh City, a place where old and new Vietnam are mixed in a vibrant chaos. The combination of city buzz, coastal calm, and historical richness makes Vietnam an ideal finale for this 3-week Southeast Asia tour itinerary.

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Bangkok is one of the must-visit destinations for traveling in Southeast Asia..

Route 2: Cultural Discovery – Ancient Temples & Heritage Trails

This 21-day route is all about history and culture. Start your trip in Thailand by visiting the royal temples and palaces in Bangkok. Then go to the old capitals of Ayutthaya and Sukhothai. From grand ruins to preserved buildings, each site tells a different story about Thailand's past. End in Chiang Mai, where traditions blend with modern creativity.

Next, go to Cambodia for five days and travel between Siem Reap and Phnom Penh. Watch the sun rise over Angkor Wat, then visit smaller temples like Ta Prohm and Bayon. Go to the Royal Palace and museums in Phnom Penh that tell the story of Cambodia's long and complicated history and how strong it is.

Travel from Hanoi to Hue, Hoi An, and finally Ho Chi Minh City to end your trip in Vietnam. Every city adds something to the story, from imperial dynasties and colonial influences to the modern spirit of Vietnam. The pace is slow, which gives you time to learn about the history and connect with the local culture.

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Tourists enjoy the sunrise at Angkor Wat.

Route 3: Nature & Beach Escape – Relaxation and Scenic Beauty

If you prefer green landscapes and relaxed beach days, this Thailand Vietnam Cambodia itinerary 3 weeks route shifts the balance toward nature and coast. Begin in Thailand with seven days in Bangkok and the islands for sun, sand and ocean. Island hopping, snorkeling, and quiet sunsets set the tone for a relaxed start.

Continue into Cambodia for five days. Spend time at Angkor Wat and nearby temples on a Siem Reap tour, then optionally head to coastal areas for calm beaches. Mix culture with leisure and enjoy slower mornings or riverfront cafés. This blend allows you to experience Cambodia’s heritage without rushing from site to site.

Arrive in Vietnam for nine days, and have a fair city-life and nature-scenery experience. Stay in Hanoi and take a cruise on Halong Bay. Then, head down to Nha Trang or other nearby coastal areas. You can either lie on the beach, watch the limestone karsts or walk through the green hills. This journey is all about peace and quiet, presenting you a beautiful nature escape while still being able to glimpse the main attractions.

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Taking a luxury cruise in Halong Bay is a special experience..

Route 4: Adventure & Local Experience – Thrills and Authenticity

For those wanting to push a little further off the beaten track, this Thailand Cambodia Vietnam 21 days plan offers adventure and local engagement. Start in Thailand. Hike the hills, see the local villages, and unwind in hot springs. Wander through markets, eat regional dishes, and meet locals on your way. This part is a combination of culture and outdoor fun for an immersive intro.

After that, spend five days on Cambodia tours, touring Siem Reap and Kampot. Ride your bike through temple ruins, visit pepper farms, and enjoy river kayaking. Small towns and local experiences reveal the daily life that is different from the tourist hotspots. It’s a combination of the past, adventure, and getting to know the locals.

End with ten days in Vietnam, from Hanoi to Sapa, then Halong Bay, Phong Nha, and Ho Chi Minh City. Walk the highland trails, cruise through sea caves, explore underground rivers, and immerse yourself in lively city life. This trip is a combination of the exhilarating, the natural, and the urban, so it will stay with you for a long time as a truly adventurous Indochina journey.

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Tourists are hiking in beautiful terraced fields in Sapa.

Customizing Your 21-Day Thailand Cambodia Vietnam Tour

The routes above are just examples, not set schedules. You can change them based on what you like, when your flights are, and how much energy you have. If you want to spend more time at the beach for Indochina tour, take a few days off from the cities and add them to Phuket or Nha Trang. If you like culture more, skip the beaches and stay in Siem Reap or Hue for a few extra days.

You can also choose your starting point based on flights. Many fly into Bangkok and out of Ho Chi Minh City, but starting in Hanoi and ending in Bangkok works too. The key is to keep the route smooth without unnecessary backtracking. Build in rest days to recharge—three weeks might seem long, but constant travel can be tiring.

With Indochina Tour, your trip becomes even more seamless and enjoyable. Our local team helps you craft an itinerary that fits your pace, interests, and budget. We handle all the details, from flights and accommodations to transfers and guided tours, including the best places to visit in Thailand Cambodia and Vietnam. So, you can focus on experiencing the culture, nature, and cities without stress.

Feel free to contact us anytime to create a customized 21-Day Thailand, Cambodia, and Vietnam tour that brings your dream Indochina adventure to life.

Three-country Tour lets you experience three distinct Southeast Asian cultures in one trip.

Travel Tips for a 21-Day Thailand Cambodia Vietnam Itinerary

When you're planning your 21-day trip to Thailand, Cambodia, and Vietnam, visa rules are one of the first things you should look into. The majority of travelers are able to obtain a visa on arrival or online. But it's wise to check the regulations for your passport prior to your departure. Keep your papers handy and have onward travel proof – it makes crossing the border a whole lot easier.

It is easy to travel around the area. Short flights, trains, and buses connect the major towns, and taxis, tuk-tuks, and local ferries make it easy to discover them once you are there. Sleeper buses or overnight trains in Vietnam are an excellent option for traveling long distances without spending on a night's lodging. Mixing the right combination makes your trip easy rather than frantic.

Cash and connectivity are essential. Bring local currency for street food, tips, and small buys, and reserve a card for larger transactions. Pick up a local SIM card or a roaming package so you can access maps, timetables, and reservations on the move. Connectivity will allow you to move freely and make the best of each destination.

21 Days to Explore the Culture of Thailand, Cambodia and Vietnam

Bangkok – Chiang Rai – Golden Triangle – Chiang Mai – Siem Reap – Saigon – Mekong Delta – Hoi An – Hanoi – Halong Bay – Hanoi – Sapa - Hanoi

Conclusion

A 3-week Vietnam Cambodia and Thailand trip gives you time to see the best of Southeast Asia without rushing. You will pass through temples of the ancient times, dine on the street food of the noisy cities, be at ease on the beaches of tropics, and come across people whose lives are totally different from yours. You can mix and match parts from all four routes to make something that fits your style.

Each traveler has a unique experience of Southeast Asia, and thus, your journey should be different from others. Indochina Tour is able to assist you in mixing the temples, beaches, cities, and nature in such a manner that it suits your tempo. Contact us and let's get the unforgettable journey lined up.