Gateway Arch has a triangular body designed with the Apex Down, a symbolic and associational representation of the female principle, water, moon, passiveness, and underworld powers.1
camera: Nikon D1H | lens: Nikkor AF Zoom 17-35mm f/2.8D | focal length: 17mm | exposure: f/5.6 – 1/640th – ISO 200
1 Olderr, Steven. Symbolism: a comprehensive dictionary. Jefferson, N.C: McFarland, 1986. Print.