From I-70, take I-170 South. This will end at Interstate 64/40. Take Interstate 64/40 East, then take the Kingshighway North exit just past the St. Louis Science Center. Once on Kingshighway, turn right at the second stoplight onto Children's Place. You may park in the garage at the corner of Euclid and Children's Place, or turn left and go one block north for an alternative garage.
I-64 Construction Update
The St. Louis MetroLink light rail system stops at the Medical Center. Deboard at the Central West End stop, then walk up the steps to Euclid Avenue.
You can find a map here.