Travel to the Thai- Cambodian border (Aranyaprathet). You will pass through Immigration at the border and a guide from Cambodia will meet you at Siem Reap. On the way you will visit the Killing Fields Pagoda and Stone Carving.
Then the trip goes to the hotel to check in and stay overnight.

After breakfast we visit Banteay Srei temple and Taprohm temple. You will see the South Gate of Angkor, Bayon, Terrace of Elephant, Terrace of Leper King, Former Royal Palace, and Pahoun Phimean Ahaz Temple. After lunch it is Angkor Wat temple and enjoy the sunset  on Phnom Bakheng. Stay overnight at the hotel.

After breakfast there is a visit to Phnom Phen. After lunch we will see the National Museum, Royal Palace,
Wat Phnom and it is time for shopping at the local market. Then it's back to the hotel for stay overnight.

After breakfast we will go to Sihaoukville by boat or car depending on the weather and after the tour you can relax and do as you wish.
Stay overnight at the hotel.

After breakfast, you will go from Sihanoukville to Koh Kong and on the border you will have help to get your passport stamped correctly. After the border crossing is the transport back to Pattaya.