WELCOME TO SOUTHIE

Mass Underground is excited to announce the opening of our second location on East 1st & K Street in South Boston! Memberships are now available for purchase. Stay tuned for information regarding our Opening Day, coming this Spring 2025!

SOUTH BOSTON MEMBERSHIPS

YEARLY

For the best deal, commit for 1-year!

$129/Month- Billed Monthly

6 MONTHS

Option to join for a 6-month commitment.

$149/Month- Billed Monthly

MONTHLY

Not ready for long-term? Join our monthly membership!

$179/Month

JOIN NOW

INCLUDED AMENITIES

Every Mass Underground, Southie membership includes access to all of our cardio equipment, machines, free weights, saunas, ice baths, lockers, and facilities.

Your membership grants you access to our South Boston location Monday-Sunday, 365 days.

LAST CALL 🔐‼️

Presale pricing ends TOMORROW!
Join now = locked-in rates for life. (Yes, life.)

Still on the fence?🤔 Come by during our extended open house hours TOMORROW 5/2: 7–9am or 12–6pm and see for yourself!

Anyone who joins our exclusive presale will receive an MU hat or shirt, be kept in the loop on our opening day(!), and receive their discounted rate… forever ♾️

📩 DM us with any questions!

LINK IN BIO to join 🔗

#southboston #southie #bostonfitness #lifting #weighlifting #gym #newgym #massunderground

Fake candids, real gym 😃

Drop-In Open House Tours:
Monday–Friday, 7–9AM + 4–6PM, every half our on the half hour!

Drop in, look around, hear the spiel. If you’re looking for confirmation to join our presale, or if you’ve already committed- now’s your chance to see what we’re working with. Can’t make it? DM us, we’ll work something out. See you then!

#southboston #bostonfitness #boston #southie #lifting #workout #gym #openhouse #gymtour #massunderground

VIRTUAL TOUR 👀

In-person tour dates/times will be announced sooner than you think! Stay tuned for more info on when and how you can come see the space IRL. We can’t wait to meet all of you‼️

A limited number of discounted PRESALE memberships are still available- DM us with any questions!

#southboston #bostonfitness #liftinggym #saunas #icebath #weightlifting #southie #massunderground

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@fettlefitnessequipment
@thecoldlife
@roguefitness
@matrixfitness
@redwoodoutdoorsco
@arsenal_strength
@hammerstrengthofficial

📸 @petercano.video.audio

Plate by plate this thing is starting to look and feel EXACTLY how we dreamed it up. The countdown is officially on (stay tuned, it’s sooner than you think!) 🏁

#southie #bostonfitness #southboston #gym #comingsoon #boston #bostongym #massunderground

ZERO rest days😵‍💫 but worth every second! Could not do this without all of the physical, mental, and emotional support from this incredible community.

COMING (so) SOON!

#bostonfitness #southboston #gym #southie #workoutwithus #bostonworkout #massunderground

We are cruisin 🚀 Bathrooms and showers are coming to life- this not so glamorous, but absolutely necessary project is on its way to completion.. which means we’re one day closer to opening our doors 👀

#bostonfitness #southboston #opengym #liftinggym #southie #gymlife #gymdemo #workout #massunderground

Weights and lifting equipment are a given, but we’re fired up about our cardio plans too😮‍💨

What are you most pumped about? Tell us!👇

#bostonfitness #boston #southie #gym #cardio #liftinggym #southboston #massunderground

SNEAK PEAK👀🔥🥶

Our space is changing quite literally everyday and we could not be more excited about all of the progress that’s been made so far!

🔜 Stay tuned for more updates (including when/where we’ll be opening!)

#southboston #southie #bostonfitness #gymrenovation #gym #fitness #sauna #icebath #comingsoontoboston #comingsoon

Making moves and clearing out the mess so we can open our doors ASAP, Southie!🧹

🎥 Shot & Edited: @petercano.video.audio

#bostonfitness #southie #southboston #bostongym #demoday #painttransformation #comingsoontoboston #comingsoon

Nothing like a delivery day in the middle of winter to remind me I chose a career that requires heavy lifting before the workouts even start. Thankful for all of the mental and physical support 🚛💪

New equipment is in now from @arsenal_strength thanks to @jordanclarke.ak (and some unpaid family volunteers)😏

#GymOwnerLife #WhyDidIDoThis #BostonFitness #Southie #SouthBoston

Big things happening at the Southie location throughout the next few weeks 🚧

Follow along for behind-the-scenes updates while we build this thing from the ground up🔥

#southbostongym #bostonfitness #lifting #gymlife #southie #boston #gymdesign #massunderground

One month ago we walked through with a vision💭

Follow along to see where we’re at- and where we’re going 🚀

#massunderground #bostonfitness #boston #gymowner #buildout #renovation #gyminspiration #southie #southboston

Exploring our new neighborhood🍀
We can’t wait to lift with you, Southie 🔜🏋️

#SouthBoston #MassUnderground #BostonGym #Lifting #BostonFitness #Fitness #Southie

The Next Episode ✔️

Southie📍
Spring 2025

#southboston #southie #bostonfitness #bostongym #comingsoon #opengym #massunderground #boston

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CONNECT WITH US

@massunderground.southie