Angkor Archaeological Park, located in northern Cambodia and declared a UNESCO World Heritage site in 1992, is one of the most important archaeological sites in Southeast Asia. Many temple ruins are within the Angkor Archaeological Park of several capitals of the Khmer Empire of the 9th to the 15th centuries, including the largest pre-industrial city in the world. The most famous are the Temple of Angkor Wat and, at Angkor Thom, the Bayon Temple with its countless sculptural decorations.
The temples of Angkor are highly symbolic structures. The foremost Hindu concept is the temple-mountain, where the temple is built as a representation of the mythical Mount Meru: this is why so many temples, including Angkor Wat itself, are surrounded by moats, built in a mountain-like pyramidal shape and topped by precisely five towers, representing the five peaks of Mount Meru. The linga (phallus), representing the god Shiva, was also critical and while the lingas themselves have largely gone, linga stands (carved, table-like blocks of stone) can be found in many if not most rooms in the temples. There was also a political element to it all: most kings wanted to build their own state temples to symbolize their kingdom and their rule.
One element that continues to mystify archaeologists is the baray, or water reservoir, built in a grand scale around Angkor: for example, the West Baray is a mind-boggling 8 km by 2.3 km in size.
Most people took tour package and rushed via the temples in one day. Some people hired tuk Tuk and a driver to spend two days in the park. Me and some backpackers chose to ride on bicycles in 88f which was a physical challenge itself.
My lady bike has only one speed and I got a flat tire at the first temple. Fortunately the park staffs directed me to a close by repair booth. The second incident was I forgot which gate of a big temple that I parked my bike so I run around like crazy and worrying whether my bike was stolen and a plan B.
I kept on drinking water and felt exhausted the whole day. I felt temple-out by noon but stuck with my route until I finished the 18-mile small circle by 4 pm. It was more of a boot camp than vacation.
When I was in Cusco, Peru touring while waiting for my machu pichu inca trail hike, I had three days of city tours in buses with best and cool weather and did not get tired with various types of ruins. Here the shapes and forms of ruins are too similar and the heat took a big toll on my body. Climbing up the steep steps to reach different tiers were tiring.
I did the Little Circuit (Le Petit Circuit) the first day taking in major sites to the east of Angkor Thom. I then finished the Big Circuit (Le Grand Circuit) on the second day, taking in major sites north and further out east.
I was much more prepared on the second day and I biked about 22 miles. I was planing to visit another site in the afternoon, but stopped by a heavy rain. I stayed in the hotel washing clothes, taking a shower, drinking a Cambodian beer and having lunch. I got a cold and started coughing. I hope it was just a cold. There are many contagious diseases in Cambodia.
After taking antibiotics, I still felt off, but I was determined to check out two other far out sites. I hired a motorbike with the driver. I first visited the Roluos group. The ruins here are from the ancient capital of Hariharalaya, dating from the late 9th century and thus predating Angkor itself. Bakong was impressive which was a five-terraced pyramid in the mountain-temple style.
I then visited the Banteay Srey, 37 km north of Angkor Wat. This red colored temple is well known for its intricate carvings, and is worth a half day trip on its own, since it is a bit further from Siem Reap than the main Angkor Thom and Angkor Wat areas. Unfortunately, the return motorbike ride cosmetic with heavy thunderstorms. I was soaking wet and fearful for my life to be taken by the thunders, flooding roads, other bigger vehicles zooming by us. I made it back to the hotel safely, but my cold got worst.
After trying my best yet could not dig myself out of the gem scam, I carried out my plan to north regardless of my awful mood. The 15-hr train ride extended into 18-hrs and it was hot a lot of time. I was dehydrated, hungry, and still sick during the ride. I really felt to drop the whole trip and fly back to Washington DC. But I survived the ride, and try to enjoy the trip without worrying too much about the gem scam.
Chiang Mai is the hub of Northern Thailand, and Located on a plain at an elevation of 316 m, surrounded by mountains and lush countryside, it is much greener and quieter than Bangkok. 
Our main interest was the Wat Phrathat Doi Suthep which is 18 km from town, sitting at a 1,073 m elevation on the slopes of Doi (Mount) Suthep. Built in 1383 during the Lanna Thai period, legend has it that the temples site was selected by an elephant sent to roam the mountain side, where upon reaching a suitable spot, it trumpeted, circled three times, knelt down and promptly died. The temple offers grand views over the city after accenting the 300-plus steps of the Naga lined stairs. 
The Bhuping Palace is also on Route 1004. This royal winter palace has lavishly landscaped gardens. The palace itself (built in 1961) is not particularly exciting, but the extensive gardens are picturesque with some amazing plant life, including carefully curated tropical flowers, as well as centuries-old trees and giant bamboo.
