I've stayed in London long enough to know better than to judge a building by its facade. Most buildings look nondescript, weird even from the outside but once inside you'll be blown away by its grandness. Take Staple Inn, home to the Institute of Actuaries, which I went on a practical visit as part of my studies. The building dates back to 1576 and looks as if it's collapsing, but it houses perhaps the grandest Great Hall I've ever seen.
The other practical visit I had was to Lloyd's. The building, upstaged by the Gherkin next door, is nevertheless eye-catching, what with the tubes and pipes (which houses electrical power conduits and ventilation) that seem so out of place. It's its practicality that makes the building beautiful in its own sense.