WHAT KIND OF CLIMATE WOULD NEED to be so thoroughly excluded? Colt Stadium, where the Astros' predecessors played, in what is now the Astrodome parking lot, is called by one history book "the only park in history where the concession stands sold more mosquito repellent than beer."

The Astrodome is significant not because it kept out mosquitoes, or sheltered from the rain, or provided air conditioning. It is significant because it excluded everything that is Houston -- and in so doing became a "near-perfect symbol" of the city.

To look at the way stadiums are built today, you might conclude that the Astrodome is an outmoded model -- the Astros' new home since 2000, Enron Field, has a retractable roof and a view of downtown. But the Astrodome strategy has spread so universally to other building types that its influence is hard to detect. It is present in strip shopping centers even: hard shells, in which chain stores place their prepackaged implants.