Our senior trip was to Washington DC and it was a nightmare!
It was arranged by a tour company that supposedly specialized in school trips. Unbeknownst to the tour company, they planned the trip smack in the middle of the Cherry Blossom Festival - a global event and the single busiest time in DC. Naturally, this caused our bus to be stuck in traffic for hours. We had to forego several museum/monument visits we had plan. On our last day, day we ate a crappy continental breakfast in our hotel around 7am, had to miss lunch due to traffic delays, and they didn't feed us again until we were a hundred miles outside of DC heading home around 8pm - at a McDonald's, no less. Not only was our intinerary thrown off because of festival traffic and happenings, but the itinerary itself allotted zero travel time on a good day - for instance, it said "Holocaust museum - 1pm-3pm. Washington Monument 3pm-4pm" ... no time for the commute. They took us to an "off broadway" production of Cats which turned out to be a second rate dinner theater in suburban Maryland, with college kids as our servers that turned into the performers after dinner. And icing on the cake - it poured rain the entire time we were in DC.
It's been 10 years since that trip and even though I cried while we were there because it was so awful, I now have fond memories