DC Oppos will have seen this mystery sign over the past 40 years - concealed since the 1970s. Yesterday DDOT took it down - it is actually a sign for the ill-fated I-695 South Leg. Only the section to Independence Avenue was completed, but it would have passed underground on the Virginia side of the Lincoln Memorial and along the mall before meeting up with the existing Southeast Freeway (the current I-695) as part of an “Inner Beltway.”