This is the best-documented record I've read in a long time, because one visitor in June 2025 wrote down everything the rest of us forget to ask.
CrossFit 4th Dimension is at Nowogrodzka 31 in central Warsaw. It holds 4.8 from 373 reviews, which is a large enough sample that the number means roughly what it says, and the record runs through May 2026.
Read This Before You Go
A visitor in June 2025: "This is the most central CrossFit gym in Warsaw. The staff are very friendly, your 1st class/drop in is free, and the vibe is good. You need a padlock for the lockers (they can lend you one). There are 2 rooms, one main hall for classes with room at the back for drop ins, and a smaller room at the front for PT sessions and drop ins. The gym is on the 5th floor of a commercial building so you cannot drop barbells, you must use the crash pads. It gets humid in summer so bring a water bottle. I didn't use the shower facilities but there were 5 or so stalls in the men's changing room."
First class free. Bring a padlock, or borrow one. Two rooms. Five shower stalls. Humid in summer. And the one that matters most: you're on the fifth floor of a commercial building, so barbells go down on crash pads, never dropped.
He counted the showers. Do you know how rare that is?
The Fifth Floor, Confirmed From the Other Side
A member in October 2025, rating it four stars: "Best CrossFit box in Warsaw! The coaches and community are super warm and welcoming, they even switched to English during class, which I really appreciated. Minus one star only because it's on the 5th floor, so dropping weights isn't easy (I'm not used to crash pads), but it's manageable. Huge thanks to Coach Nina, Coach Tomasz, Coach Michal."
Here's why this pairing is the most useful thing on the page. The five-star visitor states the crash-pad constraint as a fact. The four-star member docks a star for it. Same limitation, two different verdicts, and neither is wrong.
That's your decision made for you. If you lift heavy and you're used to dropping the bar, this building physically won't let you, and one member found that worth a star. If you can work with pads, everyone else says it's the best box in the city.
She names three coaches in praise, and I'm happy to repeat that.
English Is Actually Spoken
Three separate reviewers, across three years, independently mention it.
A visitor in April 2023: "Great CrossFit and Weight Training gym. Very nice people. Accepting of English speakers. If I lived here, this would be my gym."
A visitor in January 2026: "Great location, super central and close to the tram. They offer a mix of classes including CrossFit, HYROX, stretch/mobility and weightlifting. Coaches are very friendly and happy to explain the exercises in English."
The October 2025 member says they switched to English mid-class for her.
Three voices spanning 2023 to 2026 is a stronger signal than any single rave, because it says the practice survived staff changes. If you don't speak Polish, that's the thing you actually needed to know.
What Else Is There
A visitor in May 2026: "Hands down the best CrossFit gym not just in Poland but also in Europe. I have been to many EU countries and nowhere do you get best available CrossFit gym space, equipment, expert coaches, an expert physiotherapist onsite, and an awesome sauna just around the corner from the gym. This is now my default gym every time I do Hyrox races in Europe."
A physiotherapist on site. He's comparing against boxes he's actually trained in across multiple countries, which makes it a comparison rather than a compliment.
Note his sauna is "around the corner from the gym," not in it. That's a neighbourhood amenity, not a facility here, and I won't let the phrasing blur it.
What's Missing
No prices. Free first class is the only commercial detail on the record.
No class timetable, though CrossFit, HYROX, stretch/mobility and weightlifting are all named.
Who It's Not For
Anyone who needs to drop a loaded barbell. The building says no.
Anyone who wants a big-box gym floor to wander. This is a coached CrossFit model in two rooms.
Nowogrodzka 31, 00-511 Warszawa. Open 06:00 to 22:00 weekdays, 08:00 to 14:00 Saturday, 09:00 to 13:00 Sunday. The site is crossfit-mgw.pl and the number is +48 694 460 808.
FAQ
Is the first class free?
A visitor in June 2025 says the first class or drop-in is free. Confirm when you book.
Can I drop barbells?
No. It's on the fifth floor of a commercial building, so you use crash pads. Two separate reviewers confirm this, and one docked a star for it.
Do the coaches speak English?
Yes. Three reviewers across 2023, 2025 and 2026 all say so, and one had a class switched to English.
Do I need a padlock?
Yes, for the lockers, though a visitor in June 2025 says they can lend you one.