RateMyAgentGo to search
Log inJoin
Back 10/3400 Prospect Street Northwest
Off Market

10/3400 Prospect Street Northwest

Washington DC 20007

5
9
12
30000 sq. ft.
22173 sq. ft.
Single-Family
Last sold for $28,000,000
Mark McFaddenMark McFadden, last sold this property on 12 January 2026 after -275 days on market.

Overview

Extraordinary Halcyon House! Over 30,000 square feet in this historically designated mansion overlooking the Potomac River. Sited on a dominant 1/2-acre hill. Once owned and expanded by Mark Twain's nephew. Masterful restoration-pristine condition. Most appropriate for either a single family or a qualified non-profit group. *REGISTRATION FORM REQUIRED

Features

5 bedrooms
9 bathrooms
12 carspaces
12 garage spaces
30000 sq. ft. floor area
22173 sq. ft. lot size
Single-Family

Estimated Value

Based on this property and similar 5 bedroom single-family properties sold in Washington over the last 12 months, the estimated median property value of 10/3400 Prospect Street Northwest is $3.05m.

Median value
$3.05m
Estimated value range
$1.57m - $28m
Median days on market
34
Estimated value trend
-9%
decrease over the last 12 months
Average days on market is based on recent, comparable sales in Washington. It is only an indication of the time a property is actively listed and should not be relied upon as an accurate representation of how soon a property will be sold.

Property history for 10/3400 Prospect Street Northwest

2026
Sold
$28,000,000
12 Jan 2026 by Mark McFadden, of Compass

Happy sellers in Washington

~%

We have insufficient information to provide an overview of customer satisfaction for Washington. Viewing the agent profiles, reviews and sales for Washington can provide insights for this location.

Local market activity for 5 bedroom single-family properties in Washington

In the last 12 months, 15 five-bedroom single-family properties similar to 10/3400 Prospect Street Northwest, have been sold.

This represents a 40% increase in five-bedroom single-family properties sales when compared to the previous 12 months.

Nearby agents

Compare and contact these top performing agents who’ve delivered exception customer service for their clients in Washington

placeholder
Cynthia Howar

Sellers who recommend Cynthia Howar have praised them for being local expert and supportive

  •   5   (20 reviews)
  •  2 Reviews in Washington
  •  3 Sales in Washington
View profile
placeholder
Roby Thompson

Roby Thompson is a recommended agent for Washington.  They have 6 local sales and collected 1 local review across the last 12 months.

  •   5   (5 reviews)
  •  1 Review in Washington
  •  6 Sales in Washington
View profile
placeholder
Louis Cardenas

Louis Cardenas is a recommended agent for Washington.  They have 2 local sales and collected 1 local review across the last 12 months.

  •   5   (1 review)
  •  1 Review in Washington
  •  2 Sales in Washington
View profile
placeholder
Margaret Heimbold

Margaret Heimbold is a recommended agent for Washington.  They have 1 local sale and collected 1 local review across the last 12 months.

  •   5   (5 reviews)
  •  1 Review in Washington
  •  1 Sale in Washington
View profile
or
Skip the list and find your ideal agent to sell your propertyFind My Agent
RateMyAgent
Sales:
(619) 566-0008
Company
AboutCurrent JobsBrand Guidelines
Help & Learning
Tools and TipsHelp CenterBlog
Product
Compare AgentsTracked PropertiesSalesPlans & PricingLoginJoin
Community
Awards
Quick Links
© 2026 RateMyAgent
Privacy PolicyTerms & ConditionsLicensingSitemap