Three Must-Sees: Touch down in Bangkok and make for the Metropolitan, where the sunken tubs are built for two. Doubles from $303 (year-round). Suitably soaked, toast with champers at Lebua's Sky Bar—it's (zoinks!) 63 stories high.
Fly north to Chiang Mai; shop the Old Town district for silks, or jungle-trek aboard the back of an elephant. And when it's sleepy time, Rachamankha seduces with antique-decorated digs. Doubles from $207 (low season) and $225 (high season), with breakfast.
Ready for a seaside escape? (Yes, please!) Fly south to Sala Samui on Koh Samui island, where the villas come with private pools—we won't tell if there's skinny-dipping going on. Doubles from $227 (low season) and $283 (high season), with breakfast.
Don't Forget to Pack: Sunscreen: Pick a high SPF—those rays are serious whether you're at the beach or not.
Celeb Fans: Party peeps like Blake Lively and Bradley Cooper know that the Thai trifecta of bustling Bangkok, jungly Chiang Mai, and beachy Koh Samui is totally trippy. —E.W.