Forbidden Drive (Run) — Wissahickon Valley Park, Philadelphia, ~10 mi out and back. Gravel path along Wissahickon Creek. The best long run in the city.
Schuylkill River Trail (Run) — Philadelphia, ~8 mi. Boathouse Row at sunrise, then down to the boardwalk.
Old Rag (Hike) — Shenandoah National Park, VA, ~9 mi loop. The rock scramble makes it.
Mount Washington via Tuckerman Ravine (Hike) — White Mountains, NH, ~8 mi round trip. Check the weather twice.
Breakneck Ridge (Hike) — Hudson Highlands, NY, ~4 mi loop. Steep, short, and a great view of the Hudson.
Cape May (Swim) — New Jersey, Ocean swim. Early, before the lifeguards and the crowds.
Ditch Plains (Surf) — Montauk, NY, Point break. Forgiving waves on a long-board.