A tale of two cities?
In many ways, yes – and two eras as well. Angkor was the classical high point of Khmer civilisation from the ninth to the 15th century, and you can see what remains of the glories in the sublime setting of the temple complex of Angkor Wat.
It stands in sharp juxtaposition with the Khmer Rouge's forced evacuation of the capital, Phnom Penh, during the four tragic years of Pol Pot's regime from 1976-1979. His Maoist-driven Khmer Rouge consumed between 1.5 and 2 million of Cambodia's people through execution, starvation and forced labour. The capital was virtually depopulated: city-dwellers were forced out to rural labour camps, or marched to the "killing fields" close to the capital and executed.
You'll inevitably find yourself straddling these two eras. This tranquil corner of Indochina, bordering Thailand, Laos and Vietnam, is abundant with beautiful, jungle-infested temples. Yet the people who'll often guide you to them have themselves been damaged by the genocide; some remember it through the eyes of children and orphans, others as indentured slaves.
Evidence of the horrors perpetrated by Pol Pot can be found in the Tuol Sleng Prison in Phnom Penh, where 17,000 children, women and men were tortured and killed. The school-turned-jail, also known as S-21 ("Security Office 21"), is now on the tourist circuit, as the Tuol Sleng Genocide Museum. It houses a haunting photo gallery of thousands of terrified subjects awaiting their fate. It opens 8-11am and 2.30-5pm Tuesday to Sunday, admission US$2 (many prices in Cambodia are quoted in dollars, rather than the local currency, the riel, which trades at a rate of around 6,500 to the pound).
Won't I be trampling on tragedy?
No. Vietnam "liberated" the country in 1979 then stayed on for a further 10 years, yet in the past two decades or so Cambodia has redrawn its identity. Emerald rice fields flourish, garment factories line the roads outside Phnom Penh, and the tourism infrastructure has been transformed. Yet Cambodia is still a country where it is possible to feel like an explorer rather than a tourist. It is tapping into its rich seam of undisturbed jungles with a fledgling movement of "ecotourism"; wild elephants, leopards, tigers and black-crested gibbons are but a few of the exotica on offer here. However, unlike mountain-hemmed Laos, Cambodia can also lay claim to beaches and deserted islands.
Where do I start?
Begin your odyssey in the capital, Phnom Penh. With a population approaching 1.3 million it's a sprawling, diesel-laced city buzzing with tuk-tuks (three-wheeler taxis), street stalls, vibrant markets and dragon-topped temples. In the last few years the city has undergone a style renaissance, regaining some of its lustre as the "Pearl of Asia" with a selection of world-class boutique hotels, and equally memorable places to eat.
Probably the most romantic area is Sisowath Quay, at the confluence of the Tonlé Sap and Mekong rivers. There's a wealth of French restaurants here as well as dozens of local eateries. The Foreign Correspondent's Club (00 855 232 10142; fcccambodia.com), a local institution, has sumptuous accommodation (doubles from $125/£83 for two nights, including breakfast), chocolate leather sofas and lemon walls peppered with black-and-white war photographs. Its al fresco sunset views and Asian fusion menu have attracted photo-journalists such as Tim Page and Al Rockoff (portrayed by John Malkovich in Roland Joffe's Oscar-winning film about the genocide, The Killing Fields.
Phnom Penh's cultural highlights are the Royal Palace (open 7.30-11am and 2.30-5pm, $3/£2) and the National Museum (8am-5pm, $3/£2), both bursting with Buddhist statuary.
Some French influence?
France put its stamp on Phnom Penh between the mid-19th century and the beginning of the 20th century, and many wilting, shuttered colonial-era villas are still standing. Nursing a café au lait and croissant in shady cafés such as Comme à la Maison (00 855 23 360 801; commeala maison-delicatessen.com), you feel as if you're back in the days of pastis-drinking colonists.
The French influence is also visible in the most impressive of Phnom Penh's many markets: the Art Deco Central Market, with its enormous dome. It resembles a Babylonian ziggurat and in terms of scale could give Hadrian's Pantheon in Rome a run for its money. More prosaically, the city's so-called "Russian market" abounds in fake labels, rip-off DVDs and a food section out the back where braziers crackle and sunlight slants atmospherically through the broken roof.
Many visitors to Phnom Penh also take a taxi (or ride pillion on a motor-bike) to the Memorial Site of Choeung Ek, some 15km north of the city. Its skull-packed memorial is a chilling but dignified reminder of the many who perished. It opens 8-11am and 2.30-5pm daily, admission $3 (£2).
Set your compass north. Head by road or air for Siem Reap, the nearest town to the temple complex of Angkor Wat (see panel). Between threading your way through jungle-ridden temples you can relax your calf muscles in dozens of massage spas back in Siem Reap. Seeing Hands 4 Massage (00 855 12 78 6894) is particularly sensuous, with blind masseuses seeking out your knots and pains. Boutique hotels have sprung up by the river and at every turn there are bespoke jewellers, slick bars and "doctor fish" tubs (inflated paddling pools containing thousands of surgeonfish which nibble away at the dead skin on your feet).
The most expensive and exclusive of all is the Amansara Hotel (00 855 63 760 333; amanresorts.com/amansara), where room rates begin at $750 (£500), excluding breakfast. A little more modestly, you could indulge in the Art Deco-influenced Hotel de la Paix (00 855 63 966 000; hoteldelapaixangkor .com; doubles from $185/£123). This is a five-star palace with a soul: it sponsors a number of local projects including a weaving school for women and the Gecko Project – an orphanage for street children. The Arts Lounge Bar rotates local artists' installations, the dark wood and mint-white rooms are effortlessly chic, and the hotel's spa elevates pampering to a new level. Were it not for tuk-tuks whizzing by beyond the window, you might be forgiven for thinking you were in Manhattan.
Tonlé Sap, a giant tidal lake connected to the Mekong river, is definitely worth a visit. It was instrumental to the prosperity V C of the great kingdom of Angkor: the inhabitants were smart enough to harness its water, storing it in vast barays (reservoirs), ensuring three rice harvests per year to feed their population.
These days the lake is home to the Prek Toal bird sanctuary, regarded as the most important breeding ground in South-east Asia for endangered water birds. You're likely to see the black-headed ibis, painted storks, spot-billed pelicans and grey-headed fish eagles. Plenty of local tour operators offer trips to the lake, including transport to and from Siem Reap, a boat tour and a visit to the Prek Toal Research Station, for about $75 (£50). Nearby are a number of floating villages where locals live year round on stilted houses in the floodplain – head for Kompong Phluk for the most authentic experience.
A temple off the tourist track?
The distant summit of Prasat Preah Vihear – a much-contested Khmer temple on the disputed and potentially dangerous Thai-Cambodian border – is unbeatable. With its Central sanctuary looking down over the Cambodian plains 1,720ft below, it's the most dramatically situated of the country's treasures. To get there you'll need a sturdy 4x4 and capable driver. The journey is more than compensated for by the sublime views. The temple complex (open 8am-4pm daily, admission free) begins at the foot of the mountain ascending through five gopuras (sanctuaries), embellished in asparas (dancing nymphs), nagas (sentinel water spirits) and garudas (winged monsters).
Where can I get lost?
For pristine forests and grassland, head east for remote Ratanakiri province. The demanding road journey takes you through rarely seen heartland. Here you can picnic on fried tarantulas at Skun, pass marble sculptors fashioning roadside buddhas in Kompong Thom, or overnight at Kratie – an evocative location for seeing the endangered irrawaddy dolphin in the Mekong river.
Finally you'll reach remote Ban Lung. Stay in the Treetop Eco Lodge (00 855 11 600 381; doubles from $10/£7) and swim in the cobalt-green of Yaek Lom crater lake. Then head off for Virachey National Park (00 855 77 965 196; adventure-cambodia.com/vnp). Visitors can penetrate deep into its 3,325sq km wilderness, which is home to gibbons, wild elephants and vultures.
Some beach life?
Cool off with a visit to some of the most remote islands in South-east Asia. The gateway is the unpleasant city of Sihanoukville, but Otres Beach is a $7 (£4.50) taxi ride away. It's a pearly stretch of beach with a laid-back vista of bobbing fishing boats. Otres Shack (00 855 97793 6230; otresshack.com; $30/£20 double excluding breakfast) offers swallow-you-up beds, terrazzo bathrooms and high-spec cabanas a few feet from the water's edge.
To escape, take a longtail boat for an hour to TEN103 (jontysjunglecamp.com), a treehouse encampment on the otherwise deserted island of Koh Ta Kiev. You will discover a teal-green bay fringed by jungle and the song of cicadas. You dine communally by hurricane lamp on barbecued fish caught daily in the nearby waters – and sleeping in hidden treehouses ($9/£6) or mosquito-proof hammocks ($6/£4) is unforgettable.
Additional research by Neha-Tamara Patel and Jamie Maxwell
Angkor Wat: 12th-century temple and architectural masterpiece
The city of Angkor was hewn out of the jungle 1,000 years ago, using the enormous wealth and sheer genius of the Khmer kingdom. At the time, Khmer culture and civilisation was ascendant in Asia, and its structures were commensurately grandiose.
In the end its ambition was self-defeating; the building programme depleted the kingdom's resources and weakened its defences. Thai invaders captured Angkor in 1431, and the magnificent capital was abandoned. The complex was rediscovered in 1860 by the French archaeologist Henri Mahout.
Most of the temples in the Angkor complex have been freed from the encroaching jungle, but one has been left as they found it: Ta Prohm, as seen in the film Tomb Raider. When this vast, ornate temple was abandoned, the jungle began to take its revenge. Towers and turrets have been shrugged aside, and creepers infiltrate every man-made nook.
The heart of the Khmer kingdom was Angkor Thom, a two-mile-square compound which has survived in rather better shape. In the 12th-century it was probably the world's most populous city, with around a million inhabitants. At the centre of Angkor Thom is the Bayon: a sandstone pyramid built in single-minded celebration of the face of the god Avalokitesvara. The builders' devotion is demonstrated in the countless smiling visages grinning from every surface of the tower.
Admission to the complex costs $20 (£13) for one day, $40 (£26) for three days or $60 (£40) for one week.
Travel essentials: Cambodia
When to go
* Start planning now: the hot, wet season ends next month. The ideal months to travel are December and January, though February, March and November are also relatively cool and dry. Avoid April to October.
* The easiest option is to fly to Bangkok, Kuala Lumpur or Singapore and take a connecting flight to either Siem Reap (for Angkor Wat), or the capital, Phnom Penh.
Flights to Phnom Penh are available for around £700 return on Thai Airways from Heathrow via Bangkok. To reach Siem Reap, you could combine a fare of around £550 between London and Bangkok with a flight to Siem Reap with Bangkok Air (bangkokair.com) or Air Asia (airasia.com) for about £120 return.
* Buses form the backbone of transport in Cambodia. There are also flights between Phnom Penh and Siem Reap (for Angkor Wat) with Royal Khmer Airlines (royalkhmerairlines.com) for around $60 (£40) each way.
City transport is provided by taxis, tuk-tuks, motorbikes or bicycle rickshaws.
The Foreign Office warns "Cambodia has one of the highest rates of road traffic accidents in the region, resulting in high numbers of fatalities and injuries".
* If you fly in, you can get a visa on arrival for $30 (£20); take two passport photographs. If you plan to arrive overland, check that the border crossing issues visas; otherwise you will need to get one in advance.
* Protection against typhoid, hepatitis A and B, yellow fever, diphtheria, tuberculosis, Japanese B encephalitis and rabies may be necessary; take advice from your GP or a travel-health specialist.
* A wide range of UK adventure specialists, such as Exodus (0870 240 5550; exodus.co.uk) and Explore (0844 499 0901; explore.co.uk), include Cambodia on their Indochina itineraries.
* If you arrange your own flights but want help on the ground, local tour operators include Hanuman Tourism (hanumantourism.com) and All Concierge Services (00 855 63 636 3345; allconciergeservices.com).