Chanthaburi

Chanthaburi is Thailand's gem capital — the Friday-weekend gem market in the old town draws dealers and buyers from across Southeast Asia, trading sapphires and rubies in a scene that's been running for centuries. The old town itself is one of the prettiest in eastern Thailand: pastel Sino-Vietnamese shophouses line the river, and the Cathedral of the Immaculate Conception (the largest in Thailand) speaks to the province's Vietnamese Catholic community.

Beyond gems, Chanthaburi is fruit country. Durian orchards dominate — this is where Thailand's best durian comes from, and the annual World Durian Festival in May is a sticky, pungent, glorious affair. The coast has underrated beaches at Laem Sing and Kung Wiman, and Namtok Phlio National Park just outside town offers a pretty waterfall with pools full of sacred carp. For something different, Khao Kitchakut National Park has challenging hiking and a mountaintop pilgrimage site with panoramic views.