Mass Underground, LLC
Day pass not confirmed550 E First St, Boston, MA 02127, USA
What we found
Mass Underground, LLC is on the Boston map, but no traveller has confirmed yet whether it sells a day pass to visitors, or what it costs.
Mass Underground, LLC has 36 Google reviews and a 5 rating. The gym's site says it is members-only and does not offer day passes. No public day pass is evidenced; ask at the desk.
From our research into public reviews and the gym’s own pages, Sep 2026. Visitor access still needs confirmation.
Does Mass Underground, LLC sell day passes?
If you’ve trained here or asked at the desk, tell the next traveller. It takes a minute and earns 200 points on the community board.
Opening hours
- MondayToday4:30 AM – 10:30 PM
- Tuesday4:30 AM – 10:30 PM
- Wednesday4:30 AM – 10:30 PM
- Thursday4:30 AM – 10:30 PM
- Friday4:30 AM – 10:30 PM
- Saturday4:30 AM – 10:30 PM
- Sunday4:30 AM – 10:30 PM
Hours sourced from Google. Visitor hours can be shorter than members’ hours, so verify before visiting.
