About this crag
Extensions 4 is a bouldering crag near MetroRock Climbing Center in Massachusetts. OpenBeta lists 24 routes here, graded V3- to V8-. Route and grade data comes from OpenBeta, the open climbing database.
In your pocket
Free, no account needed. Crag maps, public-land boundaries, and your climbing log in your pocket.
Every gym, guide, and crag in your pocket
Public-land boundaries under every approach
File a safety plan for every remote wall
GPS tracking that keeps recording at the end of the approach
Scan to open it
For operators
Get your own branded surface in the Climb Hubs app and a directory listing in minutes. Bookings, digital waivers, and your whole operation live in one cockpit.
