https://www.poolinspections.com/manuals/drains/pools-without-drains.pdf

"First, let’s look at the history. Why do we have drains in the first place? To answer that question,

one need look no further than the Biltmore Estate in North Carolina. Completed in 1895, it

included a 70,000-gallon swimming pool. The Vanderbilt family would fill the pool, invite

guests from all over the world to stay for a weekend, feed them southern fried chicken and

collard greens, and encourage everyone to go for a swim. When the guests left for home on

Monday, they would pull the plug from the bottom drain and empty the pool."

We likely won't see the drain from photos, these people were rich enough to care about every detail of the look!