Thailand blends centuries-old kingdoms, glittering temples, and tropical beaches with some of the world’s most flavorful street food. From the Chao Phraya River to the misty mountains of the north and the limestone peaks of the Andaman Sea, it’s a classic Southeast Asia family itinerary that’s equal parts culture and playtime.

Across three weeks, you’ll road-trip to historic sites, hop night markets, meet rescued elephants, and learn to dive where warm water and gentle reefs make an inviting classroom. With four kids aged 11–18, this plan keeps transfer days short, balances big-ticket sights with relaxed mornings, and peppers in activities teens love.

Practical notes: Thailand drives on the left; consider an International Driving Permit if renting. Dress modestly for temples (shoulders/knees covered), carry cash for markets, and download Grab for safe, budget-friendly rides. Street food is a highlight—look for busy stalls, order what you see, and bring an appetite.

Bangkok

Bangkok is a river city of royal palaces, gilded stupas, and alleyway eats. Kids love the skytrain rides and longtail boats, while parents enjoy coffee houses, sunset views, and breezy river ferries. It’s the perfect launchpad for classic day trips—Ayutthaya’s ruins and the famous Floating and Train Markets.

For a family “road trip” feel without marathon drives, rent a car for the easy highway loops to Ayutthaya and Kanchanaburi, then return it before you fly north. Otherwise, hire a van with driver; both keep the pace stress-free and budget-friendly.

Days 1–3: Old Bangkok, River Life, and Night Eats

• Grand Palace, Wat Pho, and Wat Arun: Start early to beat the heat. Teens will recognize Wat Arun’s prang from countless photos; Wat Pho’s Reclining Buddha is jaw-dropping. For an expertly guided half day, consider:
  Bangkok Royal Road - Top 3 Major Monuments

  

• Canals of Thonburi: Hop a longtail boat to see stilt houses, peaceful temples, and monitor lizards sunning by the water. Kids love the breeze and river life.
  Bangkok Canal Tour: 2-Hour Longtail Boat Ride

  

• Tuk-tuk by night: When the city cools down, markets and shrines glow. Teens get the thrill of tuk-tuks; parents get phenomenal eats.
  Bangkok by Night: Temples, Markets and Food Tuk-Tuk Tour

  

Days 4–6: Markets & Easy Day Trips (Self-Drive or Driver)

• Floating + Train Markets: See the umbrella-down moment as a train threads through Maeklong Market, then boat the canals at Damnoen Saduak. Depart at 7–8 a.m. to beat crowds.
  Bangkok: Floating Market and Train Market Experience

  

• Ayutthaya Historical Park: Drive ~1 hr 15 min north to bike temple ruins and Buddha-in-the-tree roots at Wat Mahathat. Cool off with river prawns and coconut ice cream before returning.
• Kanchanaburi (optional 1 long day): ~2.5–3 hrs to the Bridge on the River Kwai, WWII museum, and Erawan Falls’ seven emerald tiers—great for a family picnic and swims.

Where to stay (Bangkok): For value and space, browse family apartments on VRBO Bangkok or hotels on Hotels.com Bangkok. Specific picks: riverside resort vibe at Anantara Riverside Bangkok Resort (great pools, boat to BTS), budget-friendly bunks and family rooms at Lub d Bangkok Siam (by MBK & BTS), and heritage-style family rooms at Niras Bankoc Cultural Hostel. Splurge icon: Mandarin Oriental, Bangkok.

Eat & drink (family-friendly): Breakfast at On Lok Yun (retro Thai toast and soft eggs) or Sarnies for Aussie-style coffee. Lunch at Nai Mong Hoi Thod (crispy oyster omelet) or Baan Somtum Silom (papaya salads, grilled chicken). Dinner in Chinatown at T&K Seafood (garlic crab, stir-fried morning glory), or head to Soi Rambuttri for pad thai, mango sticky rice, and buskers. Teens love Baan Khanitha’s polished Thai classics or a boat-view buffet on a river cruise:
The Newest Luxury 5-Star Bangkok Chao Phraya Dinner Cruise

Getting in and around: Book international flights on Trip.com flights or Kiwi.com. In Bangkok, the BTS/MRT and river boats beat traffic; Grab cars fit families. For day trips, self-drive is straightforward on highways; expect tolls and left-side driving.

Chiang Mai

Ringed by jungle-clad hills and temples, Chiang Mai swaps Bangkok’s buzz for old-city lanes, craft markets, and cool mountain air. It’s a hub for ethical elephant visits, waterfall hikes, and cooking classes—plus khan tok dinners and the famed Khao Soi noodle soup.

Kids can join gentle treks and zip across night bazaars; parents enjoy coffee culture, handicrafts, and slower mornings at leafy cafés. Even in the hot season, shaded courtyards and smoothie stands make exploring easier.

Days 7–9: Old City, Street Food, and Elephant Day

• Wats & walls: Walk the moat of the Old City to Wat Chedi Luang and Wat Phra Singh; pop into the Lanna Folklife Museum for context and AC breaks.
• Elephants (ethical): Meet rescued elephants with no riding, lots of feeding, and river time. Pair with Doi Inthanon or do a focused sanctuary visit.
  3-in-1: Doi Inthanon Tour, Elephant Sanctuary, and Trekking Trail

  

Days 10–12: Mountains, Waterfalls, and Night Markets

• Doi Inthanon National Park: Visit Thailand’s highest point, the Twin Royal Pagodas, and Wachirathan or Mae Ya waterfalls. Cool temps make it a refreshing family day.
  Bestseller! Doi Inthanon, Waterfall & Royal Project

  

• Markets: Saturday Walking Street (Wua Lai) or Sunday Tha Pae Market for crafts, hill-tribe textiles, and snacks. Teens gravitate to artisanal ice-cream and live buskers.

Where to stay (Chiang Mai): Compare family rooms on VRBO Chiang Mai or hotels on Hotels.com Chiang Mai. Favorites: Green Tiger House (vegetarian kitchen, tranquil pool), Green Sleep Hostel (budget bunks and privates), or for pool luxe near the Night Bazaar, Shangri-La Chiang Mai. Heritage splurge: 137 Pillars House.

Eat & drink: Begin at Akha Ama Coffee (ethically sourced) or Graph Café (creative lattes). Slurp Khao Soi at Khao Soi Mae Sai or Khao Soi Khun Yai; try Huen Phen for classic northern Lanna dishes. Night bites at Chang Phueak Gate Market—“Cowboy Hat Lady” braised pork over rice is a rite of passage. For a treat, Ginger Farm Kitchen does kid-pleasing farm-to-table plates and mocktails.

Bangkok → Chiang Mai travel: Family favorite is the overnight sleeper train (11–13 hrs) with bunks—book on Trip.com trains (~$22–60 per person). Fast option: 1h15m flight via Trip.com or Kiwi.com (often $30–70 one-way).

Phuket & The Andaman Sea

Phuket is your beach-and-islands base: soft-sand bays, jungle viewpoints, and day trips to Phi Phi and Phang Nga’s sea caves. It’s also ideal for beginner scuba—warm, clear water and protected reefs make certification fun and safe for kids 10+ (Junior Open Water).

Choose a calm-family beach like Kamala or Kata. Plan dive days with rest days between, mix in boat trips, and leave space for pool time and night markets so younger travelers don’t burn out.

Days 13–15: Settle In, Beach Time, and Sea Caves

• Beach days: Kamala and Kata offer gentler waves and plenty of shade. Hire SUPs in the morning, grab fresh fruit shakes at beach shacks, and save the hottest midday hours for the pool.
• Phang Nga Bay sea caves: Paddle under limestone arches into hidden lagoons; it’s adventurous but mellow enough for all ages.
  Phang Nga Bay Sea Cave Canoeing & James Bond Island by Big Boat

  

Days 16–18: Scuba (or Snorkel) Focus

• PADI Open Water Course (3–4 days): Teens 10–14 earn Junior Open Water; 15+ get full certification. Expect two pool/confined-water days and two boat days to Racha Yai/Noi (calm, clear) or Phi Phi (turtles, soft corals). Typical courses run ~$350–500, with all gear included. Not diving? Join the boat to snorkel—visibility is excellent.
• Rest windows: Space non-diving afternoons for naps, smoothies, and sunset walks; no flying within 18–24 hours after your final dive.

Days 19–21: Islands, Elephants, and a Floating Beach Club (Optional)

• Phiphi speedboat day: Famous cliffs, snorkeling, and a sea-view lunch—early departures beat crowds.
  Phi Phi Islands Adventure Day Trip w/ Seaview Lunch by V. Marine

  

• Ethical elephant morning: Walk forest paths and feed rescued elephants—no shows or riding; great conservation learning for kids.
  A Morning with the Elephants at Phuket Elephant Sanctuary

  

• Optional: YONA Floating Beach Club: A unique daytime hangout on a boat with pools and views; go for a family-friendly afternoon session.
  YONA Beach Club: Phuket's Most Incredible Boat Experience

  

Where to stay (Phuket): Search family suites on VRBO Phuket or hotels on Hotels.com Phuket. Top family picks: Sunwing Kamala Beach (family suites, kids’ clubs, calm bay), Centara Grand Beach Resort Phuket (beachfront with slides and lazy river), budget social vibe at Lub d Phuket Patong (private family rooms), or secluded facilities at JW Marriott Phuket Resort & Spa.

Eat & drink: Breakfast roti and tea at Roti Taew Nam; iced coffees at The Feelsion Café (vintage décor). Lunch at Lock Tien food court (Hokkien noodles, satay) or The Pad Thai Shop (tiny, delicious). Dinner at Mor Mu Dong (rustic, over-water salas; order crab curry and grilled fish), One Chun (southern Thai classics), or Chom Arun for sunset views of Old Town. For dessert, Torry’s Ice Cream does local flavors like coconut and butterfly pea.

Chiang Mai → Phuket travel: Direct flights are ~2 hrs via Trip.com or Kiwi.com (often $45–100). Phuket’s airport is 45–70 minutes from most beaches; prebook a minivan for six.

Family Budget Tips (applies to all three stops)

• Dining: Street food meals run $2–4; mall food courts are air-conditioned and great for picky eaters. Share plates family-style to sample more for less.
• Transport: BTS/MRT in Bangkok is cheap; in Chiang Mai and Phuket, tuk-tuks and Grab work well. For day trips, a rented car or driver for the day splits nicely across six people.
• Diving costs: Open Water ~$350–500 per person; fun dives ~$90–130 for two-tank trips including gear. Factor in marine park fees for Phi Phi/Phang Nga.
• Seasonality: Andaman seas are calmest Nov–Apr; May–Oct can bring swell on west-facing beaches—choose Kamala/Kata for shelter. Always heed local safety flags.

Departure: Fly Phuket → Bangkok or onward internationally via Trip.com or Kiwi.com. Leave 24 hours after your last dive before flying.

At-a-glance 21-day flow: Days 1–6 Bangkok (temples, canal tour, floating/train markets, Ayutthaya/Kanchanaburi). Days 7–12 Chiang Mai (Old City, elephants, Doi Inthanon, markets). Days 13–21 Phuket (beach days, PADI course or snorkeling, Phang Nga sea caves, Phi Phi, elephant sanctuary, free time).

This three-week Thailand itinerary keeps wow-moments high and stress low, with room to breathe between big days. You’ll leave with new dive cards, a camera full of temples and turquoise water, and a family travel rhythm that really works.