Costco out. An entire skyline in. Arlington’s Pentagon Centre could ultimately trade its big-box stores and parking lots for a massive neighborhood built directly above Pentagon City Metro: • 1,888 homes • 3.5 million square feet • Apartment, office and hotel towers • Ground-floor shops and restaurants • Nearly three acres of public space • A new network of walkable streets The Witmer and Milton are already complete but they’re only the opening act. Would you trade this Costco for a new downtown?