While the Cycladic island of Serifos has stayed blissfully under the radar for most tourists, savvy Athenians have been quietly snapping up property while preserving its dusty charms. COCO-MAT Eco Residences, opened by the eponymously named Greek sleep-product company, is emblematic of this mindset: Its 13 rooms were reclaimed from stone miners’ houses built in 1910 at the foot of a hillside, just steps from the sand and calm waters of Vagia Bay. The one- or two-bedroom units feature bedrooms on the (cooler) bottom floor and living spaces and kitchenettes above (they’ll do the grocery shopping); you choose your mattress preference from the brand’s sustainably made line. Carved into the cliff face, the Lounge Bar serves buffet breakfast in the morning, lunch and light snacks during the day, and dinner in the evening—including right on the shore (for an additional charge). The hotel also supplies car or motorcycle rentals should you want to explore the island, and also will arrange diving trips and excursions to different beaches.