Contact Us We see patients listed at the three locations noted below.If you have any questions, please send us an email at CardiacFitness@childrens.harvard.edu or call us at 617-919-6617. Boston Children's Hospital 300 Longwood Ave. Boston, MA 02115 Get Directions Boston Children's Waltham 9 Hope Ave. Waltham, MA 02453 Get Directions Boston Children's Weymouth 200 Libbey Parkway Weymouth, MA 02189 Get Directions