A property management CEO says the key ingredient to successful real estate investing isn’t just location — you also need natural boundaries

Real estate experts know how important location is when it comes to making a new investment.

And according to seasoned investor Tony Julianelle, who also serves as the CEO of property management firm Atlas Real Estate, there’s a way for buyers to assess a city’s long-term investment potential and make the most of their investments.

The rule is simple: look for cities with natural boundaries

Julianelle said certain locations have better appreciation because of their geographic boundaries and pointed out that places with natural restraints like Denver and Boise are cities with strong long-term investment potential.

“Denver is naturally constrained by mountains,” he said, adding that the city’s value is bolstered by its clearly defined natural borders.

Adding that scarcity of land builds property value, Julianelle mentioned the astronomical values of property in places like Manhattan Island — a famous natural boundary — where high prices are driven by demand for property that is naturally irreplaceable.

In contrast, “Oklahoma City is a pancake,” he said, emphasizing that the city’s development can simply keep spreading outward, and Kansas City, for example, stands in a similar position.

“It’s [Oklahoma City] never going to out-appreciate the new construction,” he said. “You don’t want that.”

This article originally appeared on Business Insider.