The southern portion of the T-Third achieves several ascents and descents. This train is
heading downhill, but there is higher ground ahead, further south.
standard sign warns that if you are paying cash, you must use this door and
transact with the fare machine, and get a transfer from the motorman to serve as proof of
payment. But in these early months of the line's operation, all rides
were free, and the rules did not apply.