Did you know that the Bay Area was created out of something called a drowned river valley? Do you know the history of how Treasure Island was created out of nothing in the 1930s? A fun new video explains this and more.

Geoff Gibson, the geography maven behind the YouTube channel Geography by Geoff, takes a special look at the Bay Area this week. And even as someone who thought they knew most of the "fun facts" there are to know about the Bay Area, this video included some surprises for me, so it likely will for you too.

Gibson begins by discussing the unique geography of the Bay, and how it was formed, not by faultline, but by rising seas after the last ice age, out of what's called a drowned river valley. The same phenomenon created the Chesapeake Bay on the East Coast, and can also be called a ria, and San Francisco Bay is ria in that it remains open to the Pacific Ocean.

Gibson also shares the fact that the peak of Mount Diablo in the East Bay has one of the largest viewsheds of any spot in the western United States, allowing you to see Mount Whitney on a clear day, and be able to see out to parts of 40 of California's 58 counties.

Learn this and more in Gibson's video below.