During a recent trip to Washington, DC, I was staying in Crystal City (on the Virginia side of the Potomac) and my meetings were in DC proper. Out of curiosity, I asked my phone if I could walk and lo and behold there is a lovely trail called the Mt. Vernon that took me on a pleasant journey. It was very different than my usual view walking next to the Columbia River – for one thing more often than not I was in tree tunnels like this one!