My brother gave me a call a couple of weeks ago and told me about Frenchman's Tower. Even though I have lived in the area for quite a few years I has not heard about it and he and I lit out for an adventure.
Sure enough by the side of a urban road in Palo Alto California is a two story round brick structure built in 1875. What a great find and a chance to do some exploring. http://en.wikipedia.org/wiki/Frenchman%27s_Tower
Use link for more info.