From shamans to seaweed on Mexico’s Yucatán peninsula, where Lake Bacalar proves a worthy beach substitute

The sweat is already lashing off me when the shaman instructs his assistant to add another red-hot, football-sized rock to the pit. The veins on the younger man’s temple bulge with the strain as he carefully ferries a smoulder­ing boulder on a shovel and deposits it on top of the other volcanic stones, sending embers fluttering into the air like fireflies. He steps back into the daylight, closing the wooden shutter behind him and plunging us into sweltering darkness once again.

As the temperature rises, so does the shaman’s chanting. Under his guidance, soon we are both swaying to and fro, invoking the spirits of our ancestors and beating out spasmodic rhythms on the traditional percussion instruments in our hands. In the glowing half-light, the condor tattooed across the shaman’s glistening chest seems like it might burst into flight as the ritual builds to a crescendo, after which he throws open the doors and lets the light and a cool breeze – which seem to be one and the same – stream into the chamber.

Stepping out onto the beach, it takes me a few moments to reconcile what I’ve just experienced with the manicured gardens and elegant thatch-roofed structures to my right. As I’m handed a chilled hand towel and an ice-cool fruit juice, I can’t say for certain that I’ve connected to the healing energy of the universe, as promised, but as hotel spa experiences go, it’s hard to think of a more memorable one.

Coming after a sometimes-gruelling six-week jaunt around Guatemala, the Mexico leg of my trip was supposed to be spent lying on beaches, sipping cocktails and frolicking in the waves, an idyllic notion scuppered by murky tides of sargassum seaweed that plague this coastline from April to August.