Calling a house “historic” is one way a homeowner can try to squeeze extra value out of a home they want to sell. But just because a house is old, it isn’t necessarily historic.

What makes a house historic? The National Register of Historic Places has rules on the matter. It says that a house is historic if it satisfies one or more of these criteria: It is associated with significant events in history; it is connected with the lives of significant people; it has distinctive characteristics, construction techniques, or other factors that make it unique; its presence yields important information about a certain time period.

To assemble a list of historic houses currently on the market, 24/7 Tempo accessed information and listings from real estate sources such as Historic Properties, OldHouses.com, and Historic For Sale.com, verifying some details with the National Register of Historic Places and other historical sources. Houses listed were on the market as of June 24, 2022. (These are the American cities with the highest concentration of historic places.)

Not every house on our list is on the National Register, but all but four of them are at 100 years old. A handful of them date from the 18th century, including one built for a Colonial-era British tax collector in Pennsylvania. The largest property on the list, an estate in Virginia covering more than 1,400 acres, is also the most expensive, priced at $29.9 million. (Have a look at the grandest historic mansion in every state.)

Click here to see historic houses currently on the market

When a house is declared historic by the National Register or local preservation groups, homeowners might qualify for funding for its restoration and upkeep. On the other hand, houses with an historic designation generally can’t be significantly altered or updated with permits or a hearing to determine whether changes can be made to it at all.