Last updated November 2 2025 at 6:07 PM
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Flats on First
Property highlights
Welcome to Flats on First, where boutique living meets luxury and comfort. Residents appreciate the modern design and top-tier appliances that make life here both stylish and convenient. Outstanding amenities like a state-of-the-art fitness center and serene landscaped courtyards offer a delightful retreat. Situated in East Cambridge, the property boasts a prime location with public transportation, cultural attractions, and numerous dining options just around the corner. Reviews highlight the safe and friendly neighborhood atmosphere, perfect for those who appreciate walkability and connectivity. Flats on First embraces both cats and dogs, making it an ideal choice for pet owners seeking an upscale urban experience.
- 5 units available
- Studio • 1 Bed • 2 Beds • 3+ Beds
- Location
- 21 Charles Street, Cambridge MA 02141, East Cambridge
- Amenities
- In unit laundry, Patio / balcony, Dishwasher, Pet friendly, 24hr maintenance, Garage + more
- Price range (base price, 12 month lease)
- $3,427+ mo - $5,709+ mo
- Commute
Price and Availability
Flats on First apartments start at $3,427/month. There are 5 available apartments priced from $3,427 to $5,709. Prices were last verified by Flats on First 1 hour ago. (Prices listed include base rent only—contact the property for full details.)
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Unit 316B
Avail. Dec 5
$3,427+ moBase rent12-mo lease
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Location
Amenities
In unit laundry
Patio / balcony
Dishwasher
Pet friendly
24hr maintenance
Garage
Unit Amenities
in unit laundry
patio / balcony
walk in closets
stainless steel
air conditioning
dishwasher
bathtub
carpet
garbage disposal
ice maker
microwave
oven
range
refrigerator
smoke-free units
Property Amenities
pet friendly
clubhouse
courtyard
fire pit
24hr gym
game room
parking
bbq/grill
bike storage
garage
internet access
media room
package receiving
cats allowed
dogs allowed
accessible
elevator
24hr maintenance
business center
cc payments
lobby
online portal
smoke-free community
Flats on First embodies the best of boutique living, combining the luxuries of a modern apartment community with the comforts of a close-knit neighborhood. Come home to a place of sophistication and serenity in East Cambridge.
Verified reviews
Property Details (Fees & Lease)
Must have 3x the rent in total household income (before taxes)
Pets allowed
Cats, dogs
rent
$85
limit
2
restrictions
100 Ib combined weight limit; Breed Restrictions Apply
rent
$60
limit
2
Explore the Area
Brothers Marketplace
0.4 mi
Star Market
0.5 mi
Savenor's Butcher & Market
0.6 mi
Nourish Your Soul
0.7 mi
Whole Foods Market
0.8 mi
The Similans
0.1 mi
Helmand
0.1 mi
Boca Grande
0.1 mi
Toscanini's Ice Cream
0.1 mi
The Cheesecake Factory
0.1 mi
Cambridge St @ Third St
0.3 mi
Cambridge St @ Third St
0.3 mi
Lechmere
0.3 mi
Lechmere
0.3 mi
Lechmere
0.3 mi
Tailwind Boston Seaplane Base
2.6 mi
Boston Harbor Seaplane Base (Cape Air Seaplanes)
2.6 mi
Logan International Airport
3.4 mi
Laurence G. Hanscom Field
12.8 mi
Norwood Memorial Airport
13.2 mi
7 /10
Community Charter School of Cambridge
Charter6-12
365 Students
0.3 mi
3 /10
Kennedy-Longfellow School
PublicPK-5
293 Students
0.5 mi
5 /10
Fletcher/Maynard Academy
PublicPK-5
296 Students
0.9 mi
1 /10
Clarence R Edwards Middle School
Public6-8
306 Students
1.0 mi
5 /10
Cambridgeport
PublicPK-5
342 Students
1.0 mi
Data provided by GreatSchools. Ratings are based on test scores and additional metrics when available.
Costa Lopez Park
0.1 mi
Charles Park
0.1 mi
Timothy J. Toomey, Jr. Park
0.1 mi
Front Park
0.2 mi
Cambridge Parkway
0.2 mi
Multicultural Arts Center
0.2 mi
Orangetheory Fitness
0.2 mi
The Foundry
0.2 mi
Skate @ Canal District Kendall
0.3 mi
Percy Howe Memorial Library
0.3 mi
Child Street Dog Park
0.4 mi
Charles Street Animal Clinic
0.6 mi
Unleashed
0.9 mi
Zero New Washington St Dog Park
0.9 mi
Fish & Bone
1.2 mi
Getting Around
Walk & Transit Scores
Walk Score: 97 — Walker's Paradise, everything you need just steps away.Transit Score: 87 — Convenient public transit options nearby available.Public Transit Access
The East Cambridge area benefits from access to public transit options, such as 59 nearby routes: 48 bus, 11 rail, 0 otherNearby public transit stops include:
- Cambridge St @ Third St (~0.25 mi)
- Lechmere (~0.29 mi)
- Cambridge St @ Sciarappa St (~0.31 mi)
- O'Brien Hwy @ Museum of Science (~0.37 mi)
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Frequently Asked Questions (FAQs)
Flats on First has 5 units available starting at $3,427 per month (base price without fees when signing a 12 month lease). Check out the Price and Availability section for the most up-to-date unit information.
In Cambridge, MA, the average rent is $2,799+ for a studio, $3,290+ for a 1-bedroom, $4,171+ for a 2-bedroom, and $4,767+ for a 3-bedroom.* For more information on rental trends in Cambridge, MA, check out our monthly Cambridge, MA Rent Report.
*Based on base prices that don’t include fees
Some of Flats on First's amenities include in unit laundry, patio / balcony, and dishwasher. To see the other amenities this property offers, check out the Amenities section.
Flats on First is not currently offering any rent specials.
Yes, Flats on First is pet-friendly.
Yes, Flats on First offers parking.
Yes, Flats on First offers units with in unit laundry.
No, Flats on First does not have a pool.
Yes, Flats on First has accessible units.
Yes, Flats on First has units with dishwashers.