Question: What city is the UNESCO World Heritage Site that Gerard of Cremona did most of his work located in?
Sentence (from "Waldschlösschen Bridge"): As a result of this project, the Dresden Elbe Valley was listed in 2006 as an "Endangered World Heritage Site" (one of two in Europe, the Medieval Monuments in Kosovo being the other one), and in 2009 became only the second World Heritage Site to be de-listed.
Relevant evidence: No