Chiang Rai

Two full days covers the White Temple, Black House, Blue Temple, and the night bazaar. Three days lets you add the Golden Triangle, Doi Mae Salong tea villages, and a hill-tribe trek. Some travelers visit as a day trip from Chiang Mai, but you'll only have time for one or two temples that way.

Absolutely. They're different experiences. Chiang Rai is smaller, quieter, and more about the surrounding province than the city itself. The temples are unlike anything in Chiang Mai, and the Golden Triangle, hill-tribe villages, and tea country aren't accessible from further south. The three-and-a-half-hour bus ride is easy. My full answer is in Is Chiang Rai Worth Visiting? The Chiang Mai vs Chiang Rai comparison has the side-by-side.

Yes. The Chiang Khong border crossing leads to Huay Xai in Laos, where you can catch the two-day slow boat down the Mekong to Luang Prabang. The Mae Sai crossing into Myanmar's Tachileik allows day visits. Visa requirements change frequently, so check the current rules before you plan a crossing.

The night bazaar runs nightly on Phahonyothin Road in the city center. It's smaller and less hectic than Chiang Mai's, with hill-tribe handicrafts, local food stalls, and a central stage with live Lanna music and dance performances. Saturday brings an additional walking street market near the clock tower.