Follow signs for Watertown. On Galen Street, go east towards Watertown. Just before you cross the Charles River, you will join Rte. 16. After you cross the Charles, move to one of the two left hand turn lanes in Watertown Square, and then turn left on Rte. 20 (Main St.). This is heading towards Waltham.
Take your second right onto Church Street (the Armenian Library and Museum is on the corner of Main and Church Sts.). The First Parish is one block upon your right. Turn right at Summer Street to reach the parking lot.
From Harvard Square take #71 bus down Mt. Auburn Street. Get off at Dunkin Donuts approaching Watertown Square. Summer St. is on the right, follow for two blocks until you see church on your left.
There is a parking lot adjacent to the church. It is available for event parking in the evening after 4:00 p.m. and on weekends after 1:00 p.m., but NOT at other times.