The Cistern at Buffalo Bayou Park opens Friday

HOUSTON (KTRK) -- "Nothing beats the first time someone sees it."

To docent, Stephanie Kiouses, the Cistern at Buffalo Bayou Park is a Houston treasure.

It was built in 1926 as a drinking water reservoir, and is reopening this weekend as an urban wonderland.

We took a short tour with Kiouses.

"There are 221 reinforcement columns, and from bottom to top they stretch 25 feet,"explains Kiouses.

If it seems massive, that's because it is just under 2 acres, or the size of one and half football fields. This unique architectural relic serves as a canvas for light and sound in a way you will not see anywhere else in the city.

The echo can last as long as 17 seconds and the light play is fantastic, creating a detailed reflection on just 3 inches of water.

In the park space above, Sycamore trees stand directly over the columns below. More than 600 people already have reservations to visit, and you can do the same, online, at www.buffalobayou.org

Friday is sold out, but reservations are required so sign up before you go.

No children under the age of 9 are permitted.

If you'd like, check out and control the live camera inside the Cistern, just click here.