With all the rain we've been having it has been a challenge to keep my daughters entertained. In an act of desperation, last week I locked one of them in a cave.

To be more precise, I took Sammy to Natural Bridge Caverns located about a half hour north of San Antonio.

The limestone of central Texas lends itself to the formation of caverns, several of which are open to the public. I've always been partial to Longhorn Caverns (I had wanted to get married there but was informed by my fiancé that I would not be marrying her in a cave), but Natural Bridge Caverns is closer so we went there instead.

As an architect, I've always been fascinated by the cave surveys that are produced to map out the interior of these subterranean spaces. On the one hand, they are crude representations of the wonderously complex underground voids and demonstrate the limitations of representing complex three-dimensional spaces on a two-dimensional sheet of paper.

image courtesy Texas Speleological Survey

That said, these are still beautiful drawings. And the spaces they describe, however abstractly, are beautiful as well. It is truly an architecture without architects; a unique type of space that was created by a natural process with no overriding design intent. Although the mechanisms of how dripstones, flowstone and the like are well understood, the fact that it creates something that we humans find aesthetically pleasing (and will pay good money to see) is fascinating.

There is a trend in architecture today to attempt to remove the designer from the process of design. The idea is that a diagram or process can be created so that a constructed algorithm becomes responsible for the building's form. I personally find this approach highly suspect - the hand of the architect inevitably guides the work and to claim otherwise is misleading. But it makes for an interesting thought experiment and in caverns we see the promise of undesigned spaces realized by simple natural phenomenon. For an architect, it is fascinating to experience spaces with no historical precedent that were designed by no human intellect.

On the other hand my daughter, who is not an architect, was much more fascinated by the puddles she was able to splash around in throughout the cavern's interior and the doodlebugs she was able to play with outside of its exit.