Biltmore House had underwater lights in its indoor swimming pool at a time when many homes were still lit with candles, oil and gas lamps. Electricity was in its formative years during the home’s construction, so Biltmore architect Richard Morris Hunt decided to wire the home with both Alternating Current (AC) and Direct Current (DC), since at the time no one knew which would become the standard. The latest technology extended all the way to the Vanderbilts’ 70,000 gallon swimming pool. Lights powered by low-voltage direct current lit the pool from under the water. Located along the sides, the lights were sealed inside glass globes protected by metal cages.