Visitor parking passes are available for parking in the lot behind the building. Before visiting Charles River, your host can email you a PDF of a visitor pass, which you must print out and display on your dashboard. Do not park along the white fence (the side closest to Star Market), which is reserved for Mt. Auburn Hospital staff and visitors. Cars without a visitor tag or Charles River employee tag can be towed.
By Public Transit
From the MBTA:
Take the Red Line to the Harvard T Station.
You can use cash or purchase Charlie Tickets for public transportation in the subway stations. If you plan to be in Boston frequently, consider getting a Charlie Card either from mbta.com or in any train station.
Catch either bus 71 (Watertown Square) or 73 (Waverly Square). This will follow Mt Auburn Street.
You pay when getting off the bus when going outbound (to Charles River), but pay when getting on the bus going inbound (to Harvard Square).
Disembark at the Star Market Bus Stop, immediately after the Aberdeen Bus Stop (CITGO and Gulf gas stations on your right). Backtrack one block down Mt. Auburn Street.
Number 625 is a three-floor stone-and-glass building on immediately on your left, in between Homer Ave & Aberdeen Ave.