Want to prevent your own condo tower from bending back and forth like a stick of rubber? Easy, hide a 50,000 gallon water tank at the top and cover it up. That's exactly what developers did for San Francisco's One Rincon Hill, the tallest residential building west of the Mississippi River. The building uses the 416,000-pound tank to create tuned liquid damper (a first for the Western U.S.), thus preventing the building from moving around if a strong enough wind comes in from the San Francisco Bay.
Though experts say it's unlikely such a situation would arise, a lack of protection against such a wind could cause feelings of motion sickness and discomfort in residents. The nearly-completed building is the largest structure built in SF in over 30 years. [SF Chronicle via Curbed SF]