Deceptively simple in appearance, One Shell Plaza has a number of surprises upon closer examination. Outwardly, it looks like any other boring concrete block. But it is the only one in downtown Houston to sport a mast like so many skyscrapers in other cities. Its base has just a slight flare to it, spreading out like a Japanese fuji. The neighboring Two Shell Plaza appears to pay homage to this flare with the windows on its lower levels. They appear in roughly triangle patterns. But in reality, this is a structural element. Back at One Shell Plaza, looking down the sides you will notice that not all of the vertical lines are of the same width. Towards the corners some are wider for added structural strength.