City Nature Challenge 2026

The City Nature Challenge (CNC) is a four-day bioblitz where cities around the world record as much wildlife as possible.

Wildlife is measured by the total number of observations, the number of species and the number of people making observations. CNC is also a great way to engage in community science and help document the biodiversity of our urban areas.

The event takes place using the iNaturalist website and app. Any observation photo, geotagged from anywhere in the seven-county Philadelphia area (Philadelphia, Delaware, Montgomery and Bucks counties in Pennsylvania, and Camden, Gloucester and Burlington counties in New Jersey) and time-stamped during the four days of the event, will count toward Philadelphia’s tally. Follow the Philly area’s progress on the CNC Philly iNaturalist page: City Nature Challenge 2026: Greater Philadelphia Area · iNaturalist

Explore along with the Academy community through our home on iNaturalist, the Academy Naturalists project group!

Visit the CNC Philly home page for detailed instructions on how to participate. This annual event is organized by Natural History Museum of Los Angeles County and California Academy of Sciences.

How to Get Involved
Download iNaturalist – Create a free account in the app or at iNaturalist.org.
Make Observations – Take photos of your findings anywhere in the Challenge Area between April 24 and April 27 and add to iNaturalist.
Join an Event or Explore on Your Own– Attend an in-person event led by naturalists and community scientists or photograph wild species in your neighborhood, local park or backyard and upload them to iNaturalist.
Spread the Word – Invite friends, family, classrooms, and community groups to join the challenge.
Identify – Continue to upload and identify your photos on iNaturalist until the results are tallied on May 9.

Washington Square & Independence Square
Monday, April 27, 2026
Noon – 2 p.m.

For this special two-hour Monday outing, we will meet at noon at the Washington Square entrance located at 7th and Walnut Streets, or you can plug this location into your map (39.947820, -75.152588). We will take our time around the park and over to Independence Square, all the way to Carpenters’ Hall, making observations via iNaturalist for the City Nature Challenge and exploring wild plants, insects, birds, mammals, fungi, and other biodiversity.

Access Features

Surface/Terrain: The park surface is composed of sidewalk, brick pathways, looser brick sections and grassy areas. The area is level with no elevations or slopes.
Public Bathroom: As there are no public bathrooms in the park, it is recommended that you use the bathroom before arrival, or use the bathroom at Independence Branch Free Library at 18 S 7th St.
The area is shady and offers ample benches.
Parking: Street parking is available.
Public Transportation: Bus Routes 21, 42
Weather: If it is actively raining, we will postpone or cancel the event. Please check our Facebook event listing by 11 a.m. on event day to confirm.
The Conservatory at Laurel Hill Cemetery West
Saturday, May 9, 2026
10 a.m. – 1 p.m.
225 Belmont Ave., Bala Cynwyd

Join Laurel Hill and ANS staff along with naturalists, hobbyists and professionals as we learn how to identify species in the cemetery and arboretum. Bring the whole family for iNaturalist tutorials, interactive games, basic exploration of taxonomy and classification, with snacks and conversation about the importance of biodiversity and environmental literacy.

The City Nature Challenge allows all to explore local ecosystems, build observation skills and contribute to real scientific research. The Academy partners with community organizations and public agencies to encourage schools, educators, families and neighborhood groups to participate and make City Nature Challenge 2026 one of Philadelphia’s most inspiring and successful community science events yet.

As Philadelphia celebrates the 250th anniversary of the United States, the City Nature Challenge offers a powerful reminder that the story of this city is still being written — not only in its historic landmarks and neighborhoods, but also in its rivers, forests, meadows and the countless species that call it home.