This house on Balmerino Drive in Stornoway would cost over £14 million to buy, according to a national property website.
The street was named as the second richest in Scotland.
A computer error has been blamed for the excessive valuation appearing on Zoopla's web pages.
The blunder has since been corrected.
Similar houses in the area are around £100,000.
The owners say the property is not for sale.
£14 million valuation put on Stornoway house
15 July 2015