Paul Allen YouTube video about the 10 Most Expensive Things He Owned. Was worth 18 Billion. On the list Many homes of course: Multiple on Mercer Island in WA, some in CA, and NY. Also bought a home in California on what was called Enchanted Hill. He destroyed the home and built nothing else on it just left it empty.(gonna dig on this wondering if it has tunnels into the hill it was built on) Has two large yachts which he would have huge celebrity parties. One yacht has two helicopter pads and a submarine and is staffed by many former navy seals.

https://youtu.be/I6tRDd3WUEE