Cool Places in US For 4-5 Day Trip?

Hi all,

Long story short, I have a bit of PTO accumulated at my current job that I plan to leave in the next few months. While I would get paid out for said PTO if I quit without using it, I'd much rather utilize it before I leave.

I live in Boston, MA and am looking to solo travel somewhere realistic in the US for a 4-5 day trip. I'd likely take a Thursday, Friday, and possibly Monday off, combined with the weekend.

I'm open to basically anywhere cool with a < $250 direct, round-trip flight to and from Boston.

Recommend any cities, national parks, or just generally cool places you think I could make this work with! Thank you all :)