Travel to Cambodia by air or via Land Border from Bangkok and Kuala Lumpur or from Changi Airport in Singapore and have fun during travel holiday in medieval times Khmer's own country history was stretching from China to today Java and the sultan of Palembang was "au par" with the rulers of Angkor Wat during that time Thais were a local subtribe in Chinas Yunnan province.
Travel to Cambodia gets continuously improved since 2016 they also have an air link between Phnom Penh and Yangon / Myanmar (Burma) several land border crossings 2 airports and a deep seaport in Sihanoukville. The gateway to the country from Vietnam Laos Thailand. In general Cambodian holidays can be cheap and good no matter where you go.
But road travel is still awful because they dont have any technical knowledge how to build country roads although they have hubdreds of UN helpers in the country who consum 4 and 5 digit dollar salary each month but are of no help for the country. They just pocket European taxpayers money and have no real use.
There is also an Air Link from Siem Reap to Phnom Penh Airport. Siem Reap is also served by some other ASEAN airlines such as Silk Air and Bangkok Airways but better forget them they are relatively very expensive. Example, Air Asia charges for the Bangkok-Phnom Penh flight Baht 1500,-. Bangkok Airways pulls Baht 4500,- and Silk Air (a subsidiary of Singapore Airlines) has also high prices. The Siem Reap flights mean travel to Angkor. Chinais the heavyweight in the air with 12 Chinese airlines operating 155 direct flights each week to Cambodia including 70 flights to Phnom Penh 82 to Siem Reap and three to Sihanoukville.
Most travel to Cambodia start at Bangkok's Mor Chit Bus terminal and proceed to the Thai border. That means leaving the coach at the Thai side go through custom and immigration on both sides and on the Cambodian side the same vehicle is waiting to carry you into the city center of Siem Reap.
That one is a bit more expensive instead finish the short from Bangkok at the border and use another transportation in Cambodia but it's worth it to be on a safe and quick ride only the road is real lousy (2017).
From Siem Reap to Phnom Penh are three variants first the coaches as pictured and second is on a speed boat on the Tonle Sap River which cost about five times as much as the road travel and there is an air link between this two most important destinations in the country.
There are two more subjects on this first on the road an interesting view into the countryside is available on the water only a few boats and some houses on stilts can be seen. The other is since the roads are real lousy partly just simple dirt roads this should be considered when choosing how to travel. All hotels are selling the tickets and you will be picked up free of charge with a tuk-tuk.