This photo is from my trip to St. Louis last weekend, taken from the base of the famous Gateway Arch. Besides the sheer scale of the structure, I was attracted to its stark, geometrical shape – almost like a mathematical equation in the form of a building. In the enlarged version, you can see the windows of the observation deck at the apex.
Gateway Arch, St. Louis, January 2010. Photo by the author. Camera details: Canon PowerShot SD1200 IS. Click for larger version.