1. Katy Perry sings: Firecracker. Featured is a scene with a tunnel below, the dark area going up a steep hillside to a fine set of buildings at the top, the old Castle District; video at http://www.youtube.com/watch?v=QGJuMBdaqIw&NR=1/
Meet Budapest at dusk.
The bridge in the video is the Chain Bridge, seen here from the Castle District side, above the tunnel:
Look for the Katy Perry video reference at http://miner.hu/, a vertical search engine focusing on references to Hungary. We did not find it. Find an overview of Miner at Everyman's encyclopedia, http://en.wikipedia.org/wiki/Miner.hu. The travel way of life is not listed as a topic, nor is history; that limits its scope.