25 outdoor things to do before summer ends

9. Hike historically

Old Croton Aqueduct Trail (41 miles)
Sight: Architectural remains of the lifeline that helped kill cholera in NYC
Until the 1830s, the city’s water supply was filthy—then we figured out how to siphon fresh H2O from upstate. Follow the aqueduct north through Westchester or south to 42nd Street. Trailhead at Van Cortlandt Park South and Mosholu Pkwy, Bronx (914-693-5259, nycgovparks.org)

Sterling Ridge Trail in Sterling Forest State Park (10.2 miles)
Sight: The origins of some serious NYC bling
In 1778, Revolutionaries strung a massive iron chain across the Hudson to ward off the Royal Navy. Genius. In one of our newest state parks, you can see the foundry where the 125-pound links of “General Washington’s watch chain” were forged. Take NJ Transit bus 197 from Port Authority to trailhead at junction of Greenwood Lake Tpke and East Shore Rd, Tuxedo, NY (845-351-5907, nysparks.state.ny.us)

Harlem Valley Rail Trail (14 miles)
Sight: No big cabooses—just beautiful scenery
In the 1800s, Manhattan’s first railway was so accident-prone that the Tenth Avenue section became known as “Death Avenue.” Now the northerly stretch of the defunct Harlem Railroad track is a paved, car-free path meandering through pastures and wetlands. Trailhead off Rte 343 in Wassaic, NY. Take Metro-North Harlem line to Wassaic (518-789-9591, hvrt.org)