Preah Vihear is perched on a hilltop with a commanding view of its surroundings. Predating Angkor Wat by 100 years, the history of the temple/fortress is somewhat unclear, but it is known to be dedicated to the god Shiva and thought to have been constructed in the reign of Suryavarman I (1002-50), with further significant additions by Suryavarman II (1113-50). Unlike most Khmer temples, the temple is constructed on a long north-south axis, instead of the usual rectangular plan facing east.
Though easily accessible from present-day Thailand, and for some years occupied by that country, the temple was nonetheless claimed by Cambodia on the basis of a map prepared during French colonial times. In 1959 Cambodia brought the dispute to the International Court of Justice, which in 1962 ruled that, because Thailand had for years accepted this map, Cambodia had sovereignty over Preah Vihear. Soon afterwards Cambodia was plunged into civil war. The temple remained open to the public from Thailand (although unreachable from Cambodia) until 1975, when it was occupied by the Khmer Rouge. It re-opened from the Thai side in 1998, and in 2003 Cambodia completed the construction of a long-awaited access road allowing Cambodians to visit the temple. In 2008, after a contentious nomination process, the temple was listed as a UNESCO World Heritage Site.
Thai and Cambodian troops exchanged heavy gunfire at and around the temple in 2008 and 2011 in connection with a dispute about ownership of surrounding land. As of November 2014, both sides continued to maintain heavily armed paramilitary police facing each other near the temple. For reasons of security, some travel specialists have recommended against tourist visits to Preah Vihear. However, the site has been peaceful since 2011 and many thousands of visitors have gone without trouble. If you go, it is advisable to confirm that the situation has remained calm.
The easiest way to reach Preah Vihear is from the town of Sra'em, 30km south. Four hotels exist 1 km west of the town center (by the roundabout), on route 2625. Prices range from $7 to $12.
Buses run directly from Phnom Penh via Kompong Thom to Sra'em, leaving in the morning and arriving in the evening. (Be careful not to book a bus to Preah Vihear since these may actually go to the town of Krong Preah Vihear and not Sra'em). They drop you off at the Sra'em central roundabout. Minibuses, once daily, $8 and shared taxis, $10, run from Sra'em to Siem Reap via Anlong Veng
Mototaxis can take you to Preah Vihear Temple from Sra'em for $15 per person, or $10 per person for groups of two or more. They refuse to rent motorbikes for self drive. There is no public transit from Sra'em to Preah Vihear, so motortaxis or hitching a ride are the only two options.
The road from Siem Reap to the base of Prasat Preah Vihear via Anlong Veng, a distance of about 210 km, is fully paved. A 4x4 or moto will be required to scale the steep road going up the hill, which you can arrange at the ticket office near the base of the hill; a 4x4 costs $25 roundtrip and a moto $5 roundtrip.
There is no public bus from Anlong Veng to Preah Vihear (public transit to Sra'em does exist.) A private car needs to be negotiated for about $50 although the starting price may be over $100 so bargain hard.
You can also reach the place on a three day motorbike trip from Kompong Thom. The highway between is completely sealed and in great condition.
Cambodian soldiers have established defensive positions near Preah Vihear, though they welcome tourists. Soldiers no longer expect gifts and are quite hospitable when you are on the ancient staircase (eastern) side. You need to stop by the ticket office at the base of hill and get a ticket ($10); passports may be asked for at the ticket office and at the checkpoint leading up the mountain. The ticket office also arranges transport by pickup truck ($25 roundtrip) and moto ($5 roundtrip). A new road for the first 3 kilometers has reasonable grades, but the last 2 kilometers are on the old road and have extremely steep sections.
The "Ancient Pathway" on the east side of the temple is now open to visitors; it's a pleasant descent with more than 2,000 steps through the forest; a modern wooden staircase parallels the largely ruined stone staircase, though two sections of old path are used. The base of the staircase (which is more preserved) can also be accessed via a well signposted graded dirt road to the east of the ticket office.
Note: citizens of Thailand were being denied access to the temple from Cambodia, with no exceptions. Some Khmer-speaking Thais have been known to sneak in with a group of Khmer visitors.
There is a crossing to the temple from Thailand, but in 2008, in response to demonstrations by Thai nationalists near the temple, the Cambodian government closed it. As of November 2014, the crossing remained closed. On the Thai side, visitors can go to Khao Phra Wiharn National Park, from which they can view parts of the temple from a distance of about half a kilometer. The park also offers stunning flora, sandstone cliffs and views over the Cambodian plains
The nearest significant Thai town is Ubon Ratchathani. The park is at the end of Route 221, but public transport options are limited and the easiest option is to charter a car for the day (1000 baht and up, plus gas). The roads are surprisingly good and, depending on how hard your driver hits the gas pedal and/or how many water buffaloes decide to cross the road along the way, you can get there from Ubon in an hour and a half.
If this is out of your budget, the nearest town of any size is Kantharalak, which can be accessed by frequent public bus in 2 hours or so from the nearby towns of Ubon Ratchathani and Si Saket. For the last leg of the trip (34 km), however, you will have to hitchhike or charter a songthaew/tuk-tuk/moto taxi.
How to get there: From Bangkok, use Hwy 1 (Pahol Yothin Rd) turn right at Saraburi into Hwy 2 (Mitraphap Rd). At Amphoe Si Khew, turn right into Hwy 24, and travel via Amphoe Pak Thongchai, Sangka, and Ku Khan. Turn right into Hwy 221, and head to Amphoe Kantaralak and keep going to the park.
From Ubon Ratchathani, use Hwy 2178 and 221 via Amphoe Varin Chamrap, Samrong, Benjalak, and Kantaralak to the park.
At the temple, the only way to get around is on foot. The 500 m elevation and the resulting breeze provide some relief, but it's still a hot and sticky 120 m (vertical) up the hill.
From the Cambodian side, you can hire a motorbike-taxi to take you up the steep ascent to the foot of the temple, but you'll still have to climb up the stairs yourself.
The Thai and Cambodian paths join together at the bottom of the slope (lower end of the adjacent map), and from here the only way is up.
There are several other minor sights in the area, accessible only from the Thai side:
There are ramshackle assemblages of shacks at both the Thai parking lot and the Cambodian base of the hill, as well as all the way along the path up the hill in the temple area itself. These sell not only the expected T-shirts, postcards and cans of Pepsi, but premium cognac and cigarettes by the carton as well: it's tax-free shopping for the Thais! As foreign visitors are few, expected to be besieged by little boys and girls shouting "Hello" and hawking postcards, but they usually take the hint after a couple of "bye-byes".
Places to eat are rarer on the ground than drink stalls, although there are some pretty basic grill stalls towards the end of the Thai parking lot shopping shacks.
For more selection and a semblance of hygiene, there are a number of roadside restaurants on the Thai side before the park entrance, along the road from Kantharalak.
Drink stalls are ubiquitous along the trail.
There are only very basic accommodation options in the immediate vicinity.
Cambodia: the village at the foot of the mountain provides two or three very basic "guesthouses" in simple wooden shacks. There is also a wooden, very basic guest house (shower and toilet outside) at the bottom of the steps, where the locals live. Shower is from a barrel of rain water and a bucket. Very, very basic but very clean. Electricity from 18:00 to 22:00. The guest house at the bottom of the steps mentioned above may not exist anymore. (Jan. 2013)
Better to stay in Sra Em, 23 kilometers to the south, with five guesthouses in a row on the Anglong Veng side of town; some of these have restaurants. Count 10usd for a double room with fan.
Thailand: the nearest place with a variety of accommodation is the town of Kantharalak (approx. 30 km), which is also the nearest place with direct bus services to Bangkok, Si Saket, Ubon Ratchathani, etc.
More distant Thai-side possibilities are the towns of Si Saket (approx. 95 km, and nearest train station), and Khu Khan (approx. 95 km, and most convenient place to stay near the border if travelling to/from Anlong Veng); and the city of Ubon Ratchathani (approx 120 km) - however, the most direct access to all these places is via Kantharalak.
If you have your own equipment, there is a campground in the Khao Phra Wiharn National Park. Call the Department of National Park, Wildlife, and Plant Life  at +66-2-562-0760.
Preah Vihear is the subject of a long-running territorial dispute between Thailand and Cambodia, and several soldiers on both sides were killed in clashes in 2008, 2009 & 2011. Both sides are trying to work out a diplomatic solution.
Land mines remain a real danger in the area, although the temple itself and the access paths have been painstakingly cleared by the HALO Trust. Stay on the beaten path, don't venture into any vegetation which has not been cleared recently, and heed the red warning signs, painted rocks and strings marking the limits of the demined area.
The cliffs are steep and no provisions are made to protect you from your own carelessness. Keep a very close eye on children.
The provincial government can be reached at tel. +66 64 393 940.