I have stayed at Angkor Discover Inn several times and always chooses to go back there.
The location is not far from the Old Market where Pub Street and other known shops are, 5 min from the center in a tuk tuk.
Its very charming, built and kept in tradition of khmer/western architecture, every room has a cosy balcony to enjoy and alot of fine places nearby to eat.
Local places.
The staff is always service minded, even at 3am in the morning ;-). The property is always clean and the GM very polite and helpfull with his guest's.
Whatever question, they can help you!!
The family was running some of the first guest house in Siem Reap, way before big hotels came into the scene. They have kept their service and standard, high level.
The only downside to the guesthouse is the breakfast or food.
If you like to have breakfast it is ordered at the restaurant across the street.
Since the guest house is not in charge of the breakfast or menu it might be unfair to actually blame this on them.
The again Im not there for the breakfast. You can find alot of good places to eat nearby.
Bicycle renting is also available or even limousine if that caters to your taste.
Since Im in Siem Reap 6-7 times a year due to work I have stayed in most hotels and guest houses there.
This is definitely one I truely can recommend.
Try it, the experience speaks for itself.
