Portugal's most sparsely populated region and one of its poorest, the Alentejo doesn't sound too promising as a family-holiday destination – especially with the super-child-friendly Algarve unfurling right below it. But sitting out on our patio at the Hotel Rural Vila Galé Clube de Campo, a glass of the estate's own wine to hand and the stars glittering overhead, I know where we'd rather be.
The hotel is within the Alqueva Dark Sky Zone, whose very low rate of light pollution made it the world's first site to receive the Starlight Tourism Destination from the Starlight Foundation, supported by UNESCO. Yet despite being in the middle of nowhere, there's plenty for the kids to do here – animal-feeding and riding lessons at the on-site mini farm (where we're surprised to encounter llamas, ostriches and mini-pigs), indoor and outdoor swimming, and quad-biking. There are also kids' clubs, and in August and September families can help with the grape harvesting. You could easily not stray far from here, lost to the sunsets fading like mirages over the vineyards while your kids run free.
We do stray, though, heading closer to the lake itself to visit stunning hilltop Monsaraz with its winding alleys, somnolent cats and views across the shimmering waters to the Spanish border. Even kids who say history is boring find the ancient castle keep with its history of illegal bullfights a compelling sight (as well as a perfect mock-battle playzone), while down the hill you can feast on local seafood beside the lake at the family-friendly Centro Nautico – and, if you're here in July, take part in the restaurant's annual star-party with its kids' games and telescopes.
For kids of a ghoulish as well as a gory disposition, Evora outside the Dark Sky Zone has the startling and strangely beautiful Capela dos Ossos, a Franciscan chapel with walls and central pillars covered with skulls and bones as a reminder of human transience. The city also has one of the Alentejo's most atmospheric and luxurious places to stay, the Hotel Convento do Espinheiro, which manages to combine adult indulgences (a spa, wine-tasting sessions in a gorgeous cellar and concerts in the jaw-dropping historic chapel) with a family welcome – you'll find indoor and outdoor pools, a play area hidden among the lush gardens, a crèche, school holiday activities and family packages in summer.
But there's more to the Alentejo than stars, bones and old chapels. Travelling east towards the region's Atlantic coastline, we discover a site that has a lot to teach other destinations about bringing history to life. Lousal, a former pyrite town, has seen the redevelopment of its once prosperous mine into a fantastically innovative and interactive museum with displays on the site's history but also zoology, botany, geology (the southern Alentejo has some of the oldest rock formations on the the planet) and, of course, astronomy. The newest in a network of 20 science centres in Portugal, the Ciência Viva, it hosts temporary exhibitions from the Natural History Museum in Lisbon and free activities for families most days in the summer holidays, as well as having a permament mining-themed softplay area for younger kids and its own excellent rustic restaurant (don't miss the pumpkin cake with coconut).
Our last stop in the Alentejo is the Tróia Peninsula, the start of a wild and spectacular beach stretching south along the Atlantic coast for a distance of 65km. Described as the Portuguese Hamptons, Tróia is said to be sought out by celebs looking to escape the crowds of the Algarve or for a bolthole closer to Lisbon, Chelsea manager Jose Mourinho and former French president Nicolas Sarkhozy and his wife Carla Bruni among them.
We see little evidence of any glitz, though, among the palms, umbrella pines and modest whitewashed houses with storks' nests on their roofs and gardens of lemon trees. Indeed, after spotting dolphins on the ferry from Setúbal, we roam the fascinating yet deserted Roman ruins at Cétobriga, once a busy sardine-salting site producing the fermented fish sauce garum. And our last night in the Alentejo is one of blissful peacefulness at the Herdade das Barradas de Serra, a family-run cork farm taking in guests, with an outdoor pool and nothing to disturb the peace or distract you from the stars save the wild boar that wander the estate, snuffling as they go.
Sunvil Discovery offers tailor-made itineraries across the Alentejo, including the abovementioned hotels. Read more about family holidays in Portugal.