Where to meet up in Boston

The columned front of Quincy Market at Faneuil Hall Marketplace in Boston, with its name in gold letters — Quincy Market at Faneuil Hall Marketplace, near the Government Center and State stations. Photo by Marco Almbauer (CC0) via Wikimedia Commons

In Boston, a group with people in Cambridge, Somerville and the South Shore usually meets downtown, where the T's four subway lines cross. The lines cross at a handful of downtown stations, so the station decides the plan more than the neighborhood does.

These are the areas groups pick most often:

Downtown Crossing and Boston Common. Downtown Crossing has the Red and Orange lines. Park Street, at the edge of the Common, has the Red Line and every branch of the Green Line.
Faneuil Hall and Government Center. Government Center has the Green and Blue lines, State has the Orange and Blue lines, and Haymarket has the Orange Line and the Green Line's D and E branches.
Back Bay and Copley Square. Copley has every Green Line branch. Back Bay station has the Orange Line and several commuter rail lines.
Harvard and Kendall Squares in Cambridge. Both are on the Red Line, a short ride from Park Street.
The Seaport. It has no subway station. Silver Line buses run there from South Station.

Getting around

The MBTA's subway guide lists typical subway hours of 5 a.m. to 1 a.m. Monday to Thursday, 5 a.m. to 2 a.m. on Friday and Saturday, and 6 a.m. to 1 a.m. on Sunday. The subway doesn't run all night.

To make the last connections, the MBTA says to reach a downtown transfer station by 12:35 a.m. Sunday to Thursday, or 1:30 a.m. on Friday and Saturday.
The transfer stations are Park Street (Red and Green), Downtown Crossing (Red and Orange), Government Center (Green and Blue) and State (Orange and Blue).
Commuter rail trains to the south and west stop at South Station and Back Bay. Trains to the north stop at North Station, which also has the Orange Line and the Green Line's D and E branches.