Question: What city is the UNESCO World Heritage Site that Gerard of Cremona did most of his work located in?
Sentence (from "Bahrain Pearling Trail"): It consists of 3 oyster beds in the Bahrain northern waters, a segment of the coast and the seafront Bu Mahir fortress in the southern tip of Muharraq, and 17 buildings in Muharraq historical town connected by a 3.5 km visitor pathway.
Relevant evidence: No