The New York Times discovers one of the literally coolest characteristics of downtown Houston — the pedestrian tunnel system:

Where is everybody?
Seared by triple-digit heat and drenched by tropical storms, midday downtown Houston appears eerily deserted, the nationís fourth-largest city passing for a ghost town.
On the street, that is.
But below, there are tunnels at the end of the light ó nearly seven color-coded miles of them connecting 77 buildings ó aswarm with Houstonians lunching, shopping and power-walking in dry, air-chilled comfort. [. . .]
Other cities, notably Montreal, Toronto and Minneapolis, are renowned for their extensive tunnel and skyway networks. But Houston may be alone in the extent and nature of its pedestrian circulation system of tunnels and skywalks that become particularly popular on days like Aug. 12, 13 and 14 when temperatures hit 102 and 101, or last Thursday, when Tropical Storm Erin flooded many streets.
It was not centrally planned; it just grew, inspired by Rockefeller Center in New York. But it is not connected to a transit network. And, befitting Texansí distrust of government, most of it is private; each segment is controlled by the individual building owner who deigns to allow the public access during business hours ó and then locks the doors on nights and weekends. Some parts, like those belonging to the former Enron buildings now leased by Chevron, are closed to outsiders altogether.
Few claim mastery of the labyrinth.
ìItís one of Houstonís best-kept secrets,î said Sandra Lord, widely known as the Tunnel Lady, a Yankee transplant who dispels the mysteries for $10 a head and roams the downtown underworld with proprietary aplomb, sometimes stopping strangers to ask, ìAnd you are?î Corporations pay Ms. Lord to orient new employees below ground, and nearly 45,000 natives and visitors have taken her Discover Houston Tours since 1988. [. . .]
The tunnels are remarkably diverse, lined with restaurants and coffee bars, boutiques, florists, shoe-repair shops, jewelers, dry cleaners, dental clinics, optometrists, pharmacies, beauty salons, barbers, copy and printing services, banks and post offices.
And they are clearly amenities. ìItís extremely difficult to be a Class A building without being on a tunnel,î said Laura Van Ness, business development director of Central Houston Inc., the nonprofit downtown organization. . . .

As the article notes, the tunnel system is largely the product of private enterprise. Sort of makes you wish that the decision on whether to invest in this to private enterprise, as well.