I actually decided to look up NBA arenas' ages just to see how totally wrong slapper is.
The DC/ESA is the 6th oldest arena in the league, trailing only Madison Square Garden (icon), Palace of Auburn Hills (Pistons), Bradley Center (Bucks), Arco (team almost moved because of its age), Oracle Arena (somewhat of a local icon in the Bay area), and the Target Center (T'wolves, one year older).
What a terrible arena name, and I thought our new one sucked.