Take I-90 (aka the Mass Pike) to exit 10 to Auburn (RT-12)/Worcester
Stay to the right going through the tolls and immediately take the 12S/20W ramp to Charlton/Sturbridge. You’ll bear right onto 12S/20W.
After a mile and a half, 12S and 20W will diverge at a huge red, white and blue gas station. Turn left to follow 12S (aka Main St.)
After about a mile you’ll see a sign for the Clara Barton Birthplace museum. Take your next right onto Clara Barton Rd.
The Clara Barton Center will come up quickly on your right after about ¾ mile.
If you’re staying at the camp overnight, or have kids or other passengers needing special assistance, drive past the Center and turn right onto Ennis Road to park closer to the camp. Otherwise, please follow parking signs to the field across the street on your left.