For sale

$1,800,000

21 Walnut St #M, Boston, MA 02108

2beds

1,038sqft

$12,678/mo

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Condominium, Townhouse

Built in 1875

1,038 Square Feet Lot

$1,727,200 Zestimate^®

$1,734/sqft

$1,001/mo HOA

What's special

Air conditioningLandscaped gardenPrivate entranceRich in architectural detailHardwood floorsSecluded patioTwo generous skylit bedrooms

Just off iconic Chestnut Street, this exceptional Beacon Hill maisonette offers the rare combination of a private entrance, landscaped garden, and secluded patio in the coveted South Slope. Rich in architectural detail and filled with natural light from abundant windows and skylights, this elegant duplex lives like a private townhouse. The fireplaced living room opens to the private terrace, while the beautifully updated kitchen features stone countertops, custom cabinetry, and stainless appliances. A spacious den overlooking the garden provides an ideal home office or dining area. Upstairs are two generous skylit bedrooms, including a tranquil primary suite with large closets and a marble bath with radiant heated floors. Hardwood floors, Miele washer/dryer, air conditioning, and deeded storage complete this rare offering, just moments from Boston Common, the Public Garden, the Charles River,Esplanade and all and restaurants along nearby Charles St and the Back Bay.

62 days
1,340
118

Facts & features

Interior

Bedrooms & bathrooms

Bedrooms: 2
Bathrooms: 2
Full bathrooms: 2

Primary bedroom

Features: Skylight, Closet, Flooring - Hardwood
Level: Second
Area: 154
Dimensions: 14 x 11

Bedroom 2

Features: Skylight, Closet, Flooring - Hardwood, Window Seat
Level: Second
Area: 117
Dimensions: 9 x 13

Primary bathroom

Features: Yes

Bathroom 1

Features: Bathroom - Full
Level: Second
Area: 54
Dimensions: 9 x 6

Bathroom 2

Features: Bathroom - Full, Bathroom - With Shower Stall
Level: Second
Area: 30
Dimensions: 6 x 5

Dining room

Level: First
Area: 154
Dimensions: 11 x 14

Kitchen

Features: Flooring - Stone/Ceramic Tile
Level: First
Area: 165
Dimensions: 11 x 15

Living room

Features: Flooring - Hardwood, French Doors, Exterior Access
Level: First
Area: 216
Dimensions: 12 x 18

Heating

Baseboard

Cooling

Heat Pump

Appliances

Laundry: In Unit

Features

Closet, Entrance Foyer
Flooring: Flooring - Stone/Ceramic Tile
Doors: French Doors
Has basement: No
Number of fireplaces: 1
Fireplace features: Living Room
Common walls with other units/homes: Corner

Interior area

Total structure area: 1,038
Total interior livable area: 1,038 sqft
Finished area above ground: 1,038

Property

Parking

Parking features: On Street
Has uncovered spaces: Yes

Accessibility

Accessibility features: No

Features

Entry location: Unit Placement(Courtyard)
Patio & porch: Patio - Enclosed
Exterior features: Courtyard, Patio - Enclosed, Garden
Fencing: Security

Lot

Size: 1,038 Square Feet

Details

Parcel number: W:05 P:01573 S:006,1437388
Zoning: CD
Other equipment: Intercom

Construction

Type & style

Home type: Townhouse
Property subtype: Condominium, Townhouse

Materials

Brick

Condition

Year built: 1875

Utilities & green energy

Electric: 110 Volts
Sewer: Public Sewer
Water: Public

Community & HOA

Community

Features: Public Transportation, Shopping, Tennis Court(s), Park, Walk/Jog Trails, Medical Facility, Bike Path, Conservation Area, Highway Access, T-Station
Security: Intercom

HOA

Amenities included: Hot Water
Services included: Heat, Water, Sewer, Insurance, Snow Removal
HOA fee: $1,001 monthly

Location

Region: Boston

Financial & listing details

Price per square foot: $1,734/sqft
Tax assessed value: $1,458,100
Annual tax amount: $16,885
Date on market: 8/13/2026

Estimated market value

$1,727,200

$1.64M - $1.81M

$5,364/mo

Price history

Date	Event	Price
9/9/2026	Listed for sale	$1,800,000$1,734/sqft
Source: MLS PIN #73549276 Report a problem
8/26/2026	Listing removed	$1,800,000$1,734/sqft
Source: MLS PIN #73549276 Report a problem
7/14/2026	Listed for sale	$1,800,000+12.5%$1,734/sqft
Source: MLS PIN #73549276 Report a problem
6/15/2022	Sold	$1,600,000-9.9%$1,541/sqft
Source: MLS PIN #72962211 Report a problem
6/30/2021	Listing removed	$1,775,000$1,710/sqft
Source: MLS PIN #72823443 Report a problem
4/30/2021	Listed for sale	$1,775,000$1,710/sqft
Source: MLS PIN #72823443 Report a problem
8/5/2019	Sold	$1,775,000$1,710/sqft
Source: Agent Provided Report a problem