The picture above is taken from the Weir Chamber looking back towards the town. The tower of the First Baptist Church can be seen in the background

According to the Village of Ossining Downtown Walking Tour:

The Old Croton Aqueduct Promenade is the Downtown Ossining portion of the trail that is located directly above the water tunnel of the same name. The Aqueduct was constructed from 1837-1842 to provide growing New York City with access to new fresh water supplies. The Aqueduct tunnel connected the 660 million gallon Croton Reservoir in Cortlandt with a 180 million gallon receiving reservoir located on the site of what is now the Great Lawn in Manhattan’s Central Park, allowing 85 million gallons of water to be transported each day. The Aqueduct runs the entire length of both the Village of Ossining and of Westchester County with twenty-six miles of the total forty-one mile length located north of the New York City line. An interpretive sign located at the start of the promenade contains further information on the Aqueduct’s route and history.

A nearby interpretive sign reads:

The pathway over the Croton Aqueduct arch is known as the Promenade. During the 19th and early 20th centuries, the Promenade was a popular place to stroll. Romantic and picturesque places to walk were popular venues during the Victorian era. In that period, the Promenade was also used for concerts, dances and socials. Such was the popularity that Ossining was not the only promenade along the aqueduct. A wide promenade surrounded the reservoir at 42nd Street and Fifth Avenue in Manhattan, and Frederick Law Olmstead designated a promenade to extend over the Croton Aqueduct, connecting Jerome Park racetrack with the future Van Cortlandt Park in the Bronx.

Taken with a Sony RX-100 M3.