We had a long layover in Iceland earlier this summer, so we rented a car and drove as far south as time allowed. This is what we saw.
This is really a must. The temples of the Angkor Archeological Park are truly awe-inspiring.
The complex is massive (250 square miles!!). Exploring the temples requires a ton of climbing and stamina, and the structures are far apart with little shade in between. So unless you are an architecture buff, one day is plenty!
Since there is so much info online about all the temples, I will spare you the details. I would like to note that the day pass begins at 5pm the day before, so you can watch the sunset and get yourself amped up for the following day. A great way to avoid the throngs of people is to skip the sunrise at Angkor Wat and instead, begin the morning with some of the other temples. I can't recommend this enough! We were able to stay one step ahead of the crowds, a much more enjoyable way to appreciate the architecture of the ruins and the sheer scale. Catching the sunset the night before also allowed us to leave earlier, because by late afternoon, we were so exhausted and sweaty, the last thing we wanted to do was wait until the end of the day.
After lunch, we made one last visit to the main temple, before taking off. The late afternoon at Angkor Wat is another time to avoid the crowds as they're still exploring other temples and haven't yet returned for the sunset. Walking along the cool stone corridors with beautiful golden light streaming in, surrounded by silence, was so peaceful and meditative.
(As for Siem Reap, besides the delicious Khmer cuisine, I wasn't a huge fan, so if you're not planning on visiting Angkor Wat, I'd skip it.)
The road to Pai is a hard one. With so many curves (think Highway 1 to Stinson Beach, only 50 times worse), it is certainly not for the faint of stomach. T-shirts in town proudly boast "762 Curves to Pai." But once you arrive, you see immediately it was worth it.
The tiny town of Pai is surrounded by lush mountains and epic clouds, watched over by a white buddha at the temple on the hill. It's a little hippy town filled with loads of arts and crafts and as always, delicious street food. The town is quiet during the day as there is plenty of exploration to do in the countryside, but at night it comes alive with a nightly street market, where one can shop for crafts and sample food from the endless vendors lining the streets.
The countryside is picturesque and fairly easy to navigate if you have a map. A motorbike here is $3/day and the best way to explore. There's a canyon to hike (with a terrifyingly narrow path dropping off on either side), waterfalls, hot springs (one spring is so hot, you can cook eggs in it!), look out points (I highly recommend going to the mountain above the Chinese Village at sunset or sunrise - especially after a rainfall!), river rafting, and if you're still looking for more, endless rice paddies to stare in awe at.
(Thanks to Sam Fuller for snapping the photo of me at the canyon)