This mesmerizing time-lapse shows the construction of a million-gallon Olympic pool in 30 seconds

From the 100-meter butterfly to the 800-meter freestyle, the swimming competitions at the Rio Olympics are just heating up.

To prepare for the games, American swimmers — including decorated athletes like Michael Phelps and Dara Torres — practiced in 164-foot-long pools in the US.

The pools, which were used during the trials in June and July, were newly built replicas of what the team would see in Rio de Janeiro. That meant that in late May, two Olympic-size pools were built in just 16 days at the CenturyLink Center in Omaha, Nebraska.

USA Swimming captured the impressive construction process — which took 200 builders just 10 days — in a time-lapse video. Workers first removed all of the chairs from the arena and convention center, then pieced together the pool's floor and sides.

Next, the workers installed starting blocks, filled the pool with water — combined the two pools contain over 2 million gallons — and added the lanes.

Check out the 30-second time-lapse of the construction below:

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