While the southern part of the province is on the shore of the Gulf of Thailand and thus is mostly coastal alluvial plains, the hinterlands of the province are quite mountainous. The Chanthaburi mountain range in the north has the highest elevation of the province, the 1,556 m high Soi Dao Nua Peak. The main river of the province is the Chanthaburi River.
Together with the neighboring province, Trat, Chanthaburi is a center of gemstone mining, especially rubies and sapphires. Tropical fruits are also among the main products of the province. In 2000, it produced nearly 380,000 tonnes of durian, which was 45.57% of Thailand's durian production, approximately 27% of the entire world's production.[4][5]
Within provincial boundaries lie three national parks: Namtok Phlio National Park;[6] Khao Khitchakut National Park;[7] and Khao Sip Ha Chan National Park.[8]