As I ducked through a narrow gap in the jagged limestone the first sense was of relief, as a quenching shade replaced the skin-blistering, 40-degree, pre-rainy season heat outside. My flip flops echoed around the cave as I descended the narrow flight of steps that had been cut into the rocks into what felt like a scene from an Indiana Jones film.

A shaft of sunlight pierced through a circular hole in the roof, illuminating the gloom and refracting off the vast, crystal-clear pool below. Bats fluttered above, vines crisscrossed the ceiling, and stalactites stretched down, like frozen drops of pitch. As I slipped into the bracingly cool, crystal-clear water small black catfish nibbled at my toes. For a glorious 15 minutes or so I had Cenote X’Keken, just outside the city of Valladolid, to myself.

Afterwards I braved the midday sun again to explore the nearby Cenote Samula, which is perhaps even more spectacular than its neighbour. The dome of the cave was punctuated by a sizeable hole, through which the gnarled roots of an ancient tree dangled, tantalisingly out of reach of the frigid, turquoise water below. Despite the high temperatures outside, and the fact that it was a Sunday, there was only one other person there.

The region’s network of cenotes – limestone sinkholes, generally filled with fresh water – was vital for the Mayan civilization that dominated the Yucatán Peninsula before the arrival of the Spanish conquistadors in the 1500s. And it is easy to see why they were considered sacred gateways to the Mayan underworld, known as Xibalba (“the place of fear”).

At the Cenote Sagrado, a murky green pool at the famous ruins at Chichén Itzá, for example, the Mayans threw statues, pottery, incense, textiles, jade, gold, and human sacrifices into the water as offerings to the gods of the underworld. The few human sacrifices who survived the ordeal, incidentally, were considered to have spoken with the gods, and have developed prophetic powers. (The conquistadors, rabid for gold, ransacked Chichén Itzá for the precious metal, largely in vain, unaware that the riches they sought were so close at hand.)

Many of the other cenotes in the region hold even older treasures: in recent years divers have discovered human skeletons that date back nearly 14,000 years, and even the remains of a mastodon (a prehistoric pachyderm).

Yet the cenotes, which collectively form vast largest cave systems, have an even greater significance, being linked to one of the most significant events in the history of the earth. Some 66 million years ago the Chicxulub asteroid struck the Yucatán, an event that is considered to have contributed to the extinction of the dinosaurs. The strike also caused large sections of the region’s limestone bedrock to collapse, in turn forming thousands of cenotes.

The Mayans later founded their villages and towns around these flooded subterranean chambers, which, given the lack of lakes and rivers in the region, were vital sources of fresh water. Today many of these cenotes – known collectively as the “Ring of Cenotes” – have been turned into major tourist attractions, for example, at the Xel-Há theme park near Tulum. But others are far less developed, with little in the way of facilities and few visitors.

For experienced divers with a sense of adventure – and no sense of claustrophobia – Dos Ojos (“Two Eyes”) is one of many that are worth exploring further. The water is incredibly clear here and this high visibility means photographers can get some incredible shots. And even if you don’t fancy strapping on a scuba tank, you can still have an evocative experience with a mask and a snorkel.

I finished my trip at Cenote Yokdzonot, located in a dusty, sleepy village a short drive away from Chichén Itzá. Looked after by a local cooperative, which provides a stack of lifejackets, a couple of rustic shacks to change in, and a set of rickety wooden steps, the cenote is rarely visited by foreign tourists.

Open to the elements, the deep, circular sinkhole is shaded by tall trees. After rousing the slumbering ticket-seller to pay the small entry fee, I dived into the aquamarine, seemingly bottomless water. A couple of local children splashed about, thick tangle vines spiralled gently in the breeze and tiny birds, moving too fast for the human eye to focus on, swirled above. It was a perfectly relaxing scene – at least until my mind turned to the human sacrifices that might lie at the bottom.

A version of this article was first published on www.roughguides.com.

For most travellers the hills to the west of Kathmandu mean only one thing: the buzzing resort of Pokhara, which draws many thousands of tourists every year. But the region is actually home to a wide range of little-visited attractions.

Begnas Tal and Rupa Tal

Phewa Lake helped to put Pokhara on the tourist map, but it is now crowded by an ever-growing number of hotels, restaurants, bars and shops. Just 15km to the east, however, are two equally beautiful, under-visited lakes, with little of the over-development that threatens to overwhelm Pokhara.

According to local legend, Begnas Tal and Rupa Tal are husband and wife, and if you throw something into one of them, it will eventually appear in the other. The former, the bigger of the two, is framed by impossibly steep, terraced hills, while the latter is hidden away in a lush valley just to the south. Both of the lakes have the majestic snow-capped, tent-shaped peak of Annapurna II in the background, and white egrets and ospreys flying overhead – and occasionally swooping down to snatch up a fish.

Kahun Daada

Flocks of tourists hike up the mini peak of Sarangkot, just west of Pokhara, to take in the superb views, yet similarly impressive vistas can be enjoyed in virtual isolation on the eastern edge of the city at the top of Kahun Daada hill. The route up to this viewpoint also takes you through some fascinating cultural sites.

On the outskirts of the city an exacting flight of over 200 steps takes you to the intricate Manang monastery, home to around 70 Buddhist monks and site of some superb views. A ten-minute walk from the monastery, up another few hundred steps, is the Hindu Bardakali temple, which is surrounded by flowering bougainvillea and is a popular – and suitably dramatic – spot for weddings.

From here, you pass through traditional villages before reaching several uncrowded trails to the 1442m summit of Kahun Daada. Here there are stunning views of the Annapurna range, notably the 6667m-high Machhapuchhare Mountain, popularly known as the “Fish Head” for its distinctive shape.

Manakamama

Nepal’s most famous wish-granting temple, Manakamama Devi attracts vast numbers of domestic and Indian pilgrims, but very few other foreign tourists. It is accessed by Nepal’s only cable car (www.chitawoncoe.com.np), which whisks you swiftly up 2.8km through the clouds to the hilltop temple. You may find yourself sharing a gondola with a tethered goat, pigeon or chicken – animal sacrifices are common here. After disembarking, a trail of guesthouses, tea shops, and clusters of stalls selling devotional items – including coconuts, flower garlands and gold-trimmed shawls – leads up to a small square, which bustles with energy.

There, in the shade of a giant champ tree (a type of magnolia), the two-tiered temple is surrounded by a gaggle of pilgrims, priests and sadhus (Hindu holy men, many of whom opt to walk up the hill rather use the cable car), who light candles, ring bells, chant hymns, ask the goddess Bhagwati to grant their wishes and snap photos. Beyond the temple there are superlative vistas down to the confluence of the Trisuli and Marsyangdi rivers, and across to the Himalayas.

Bandipur

It’s hard to imagine a more picture-perfect town than Bandipur. Located at the top of a series of limestone cliffs, and linked to the world below by a serpentine, winding road, Bandipur was an important trading post in the 1800s.

But road construction elsewhere in Nepal meant that it slowly fell from prominence, and today it feels frozen in time. The sleepy, vehicle-free bazaar area is filled with wonderfully preserved, nineteenth-century mansions, with shuttered windows, intricately carved wooden doors, and facades covered with creeping vines and flowers. Several of these homes have now been turned into atmospheric boutique hotels – notably the charming Old Inn – and the town is a wonderful place to relax and watch the world go slowly by. A short walk from the bazaar is the tudikhel (parade ground), which protrudes out of the ridge, with sheer drops on two sides, a line of fig trees on another and the Himalayas straight head.

Gorkha

The ancestral home of Nepal’s former royal family, and a town steeped in history, Gorkha should be an essential stop on any itinerary of Nepal, but it receives barely a trickle of foreign travellers. Its highlight is undoubtedly the magnificent eighteenth-century Gorkha Durbar, a stiff 40-minute climb up a flight of stone steps from the lower town, something that is best attempted in the morning before the heat rises.

The Durbar itself is a real feat of architecture and engineering: half palace, half temple, the brick-and-wood construction is perched precariously on a high, narrow ridge. It was from here that Prithvi Narayan Shah conquered the country’s valley kingdoms and unified the modern Nepal. The Durbar, which gazes out towards the Himalayan mountains of Ganesh Himal, the Annapurnas and Dhaulagiri, is a hive of activity during the Chait Dasain festival in late March or early April, when there are processions, ancient rites and animal sacrifices.

If you’ve got any energy left from your ascent to the Durbar, hike up for a further 30 minutes or so to the much smaller Upallokot (Upper Fort), which stands at some 1520m.

A version of this article was first published here.