Event
Friday, April 24, 2026
10 a.m. — 2 p.m.
Monday, April 27, 2026
10 a.m. — 2 p.m.
Saturday, May 9, 2026
10 a.m. — 2 p.m.
Academy of Natural Sciences
1900 Benjamin Franklin Parkway
Philadelphia, PA 19103
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.
Friday, April 24, 2026
10-2 p.m.
Join the Academy of Natural Sciences and Friends of FDR Park for the City Nature Challenge 2026 Kickoff at FDR Park! City Nature Challenge 2026
We will be making observations via iNaturalist for the City Nature Challenge, observing plants,insects, fish, birds, mammals, fungi, reptiles and other biodiversity. All walks will start and end at the Boat House.
Join CNC Philly iNaturalist Project: City Nature Challenge 2026: Greater Philadelphia Area Join the Academy Naturalists iNaturalist Project: Academy Naturalists
Follow FDR Parks iNaturalist account: fdr-phillylakes
Nature Walks
Access Features
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
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.