Diving in Cambodia's southern waters is varied and exciting. There are two shipwrecks here, about 130 feet underwater. One such shipwreck is the SS Mayaguez, the subject of a major battle between US forces and the Khmer Rouge – and the last skirmish of the Vietnam War. Trips to the area require an overnight stay at Koh Tang Island.

Off the coast of Sihanoukville lie more than 12 islands, each with unique attractions. Fishing enthusiasts will love Koh Rong, which offers excellent crabbing opportunities. Nearby Koh Rong Samlon sports excellent diving and marine life, while sleepy stilted fishing villages unveil a whole other side of enduring local life still ongoing in Cambodia's southern isles.

Six Senses' 40 pool villas offer sustainable accommodation in an Edenic setting; lush tropical foliage, jewel-toned waters, golden sands and fuchsia sunsets. There a big focus on wellness here and guests can participate in detox programs, yoga sessions in picturesque island locations, as well as groundbreaking therapies led by visiting practitioners. Create your own natural products at The Alchemy Bar, retreat into the Meditation Cave and rise to sun salutations against a backdrop of endless ocean horizon.

Song Saa is a private island resort comprised of two "sweetheart" islets and 24 villas, not far from neighboring Koh Rong. Aside from being a five-star, ultra-luxe property, this resort is also a beacon of sustainability in Southeast Asia, featuring a 12-acre marine reserve, conservation projects, gourmet meals made from locally-sourced ingredients (and fresh seafood!), and much more besides.

Back on the mainland, The Starfish Bakery and Café in Sihanoukville is run by an NGO and serves quiche, tortillas, sandwiches, salads and Western-style breakfast - worth a stop for a quick bite while you're waiting for your boat transfer. The income generated helps to fund micro-loans, as well as simple housing and medical treatments for very poor Cambodians.