S21 and Killing Fields were extremely interesting. Perhaps in hindsight, it would be more flexible to get a tuk tuk to the two museums so that you can choose how long you spend in each one. The tuk tuk driver will wait for you in each place for a similar price as the tour, if not cheaper. However, highly recommend visiting these two areas if in Phnom Penh

Using words like 'excellent' to describe such a powerful and harrowing experience feels a bit odd but: it was a good thing to do. Hats off to all the people, the staff and volunteers and survivors who run and lead visitors around the prison museum and the Killing Fields. Just for an hour or two, you understand how terrible it was, the utter mind-blowing inhumanity of the Khmer Rouge regime, the awful suffering of prisoners - who were a mixture of civil servants and teachers, artists and just ordinary people who this paranoid regime thought might be against them, or might have values that were contrary to Khmer Rouge values. And it explains why - in as much as that is possible - Pol Pot and his followers thought it was a good idea. Pol Pot wanted, in as short a time as possible, to wipe out all 'modern' things and return society to the days of the Angkor civilisation. But it seems his plan was just to destroy - and force people to work in agricultural labour camps, rather than to build.

El recorrido por la prisión S21 fue muy informativo y emotivo; definitivamente contrate un guía privado (alrededor de $ 5 USD por persona). Definitivamente valía la pena visitar los campos de exterminio, muy desgarradores. El autobús de ida y vuelta estuvo bien, muy cómodo. Y era conveniente situarse entre los dos lugares de interés.