Hop on Hop off buses are wonderful....great way to see the sights....we bought a 48 hour flex pass. The first day we rode the bus and did not get off....2nd day we used the bus to get to where we wanted to go and got off.....many extras....enjoyed Newseum immensely. Only glitch we had was with the night tour...too many people and only one bus...we were rescheduled to go 2 nights later because we went to a Nats game the next night....but it was cold and rainy so we didn't go. Guides were pleasant and overall it was well worth the $$$