The geography of Nazi German death camps in modern-day Poland is complex. First off, take a look at this map from 20th Century History @ About.com which shows the major concentration and extermination camps of World War II.
The Germans plan was to cleanse the eastern lands of Poles, Slavs, Jews, and others and turn the ethnically cleansed land over to a new, agriculturally-based German colonizing culture. Modern-day Poland was to be a key part of this bloodland. Many of the death camps were placed inside the modern-boundaries of Poland to help accomplish the goal.
However, the Nazis themselves would not have used the term "Polish camps" or even "camps in Poland" because the Nazis never fully recognized any Polish state's right to existence. The extermination camps where all west of the Vistula River, placing them within the historic boundaries of the German Empire (meaning these lands were only in a modern Polish state for twenty years).
Chelmno and Auschwitz were back in the Greater German Reich proper while Treblinka, Majdanek, and Belzec were in the "General Government", a zone which was to be cleansed and then completely aborsbed back into Nazi Germany proper as well. Meanwhile other concentration camps such as Koldichevo and Janowska were established in the old Second Polish Republic's lands (given to the Soviet Union by Nazi Germany at the start of the war) which were then politically located in Reichskommissariats Ukraine and Ostland. These lands were colonies in which long range plans called for eventual inclusion into the Greater German Reich.
Finally, one must remember that while the extermination aka death camps were located to the east of Berlin, the majority concentration camp system was established before the start of World War II and therefore located in Germany itself. The University of California Santa Barbra has a great map showing the distribution of camps used to house political prisoners and other not-necessarily sentenced to death targets of the Nazi regime.
The camps where very much part of a German system. In the eastern bloodlands of Nazi-controlled former Soviet lands much of the killings were done by Germans and other Slavic groups together. However, Poland witnessed very few cases of collaboration. The camps were in ethnic Polish lands but were politically located in various degrees of Germany and German-occupied land and were run by Germans. There was nothing Polish about the extermination camp system.