Contrast. A striking exhibition of unlikeness.

That’s how our good friends over at describe things that are wholly different than each other.

London’s Tower Bridge and City Hall were built more than 100 years apart. The design differences — from boxy to bulbous — show how a city shifts through phases and ages.

It seems they have figured out how to make new friends yet keep the old. Classics share the skyline with contemporaries. There’s room for everyone as long as royally approved sight lines to St. Paul’s remain in tact.

Seriously. According to a very knowledgeable friend, new construction can be as tall as it wants, as long as it doesn’t block traditional views of the famous cathedral. That’s why a new building — still being erected and the highest structure in the EU — has taken on the shape of a pointy shard of glass. Otherwise, it would have blocked views of the dome which have been seen above the city for 300 years.

Ah, London. Urban renewal with a keen eye toward modern aesthetics.

And tradition.