Longtime Beacon Hill residents may remember the days when 20 Charles St. was home to a Nantucket Nectars store. But those who have only been here for a few years know the spot better for its thin-crust pizzas and specialty toppings.

That spot is home to Upper Crust Pizzeria, the first store ever opened by owners Jordan Tobins, Josh Huggard and Brendan Higgins. It is now one of 17 stores across Massachusetts.

Tobins and Huggard got into the pizza business in 2001 after being disappointed by various experiences in the corporate grind. A year later, the pair — friends since childhood — moved into a Beacon Hill apartment above what would be their first pizzeria.

That move fulfilled a goal the business partners had set for themselves. "We said, 'The next office we work in will be the one we create,'" explained Huggard.

With Higgins' help, the trio has done more than just created a restaurant chain — they have developed a brand that is now recognized by people all over Boston. There's even an Upper Crust in Istanbul, Turkey, with plans to add several locations in the Washington, D.C. area as well -- and all before the pizzeria celebrates its 10th anniversary.

Beyond geography, sales volumes have grown as well. Huggard chooses not to disclose the brand's overall revenues, but does offer a reference point from several years ago when the Upper Crust brand acquired a Coolidge Corner pizzeria from outside ownership. Monthly sales at that location quickly expanded from $30,000 to $150,000.

But despite Upper Crust's rapid pace of national and international growth, Beacon Hill retains a special place in the company's financial statements. The Beacon Hill store represents the chain's best performing location, Huggard said. Even though the store doesn't have a liquor license like some other locations, Huggard said he's not surprised about the performance.

"Beacon Hill is such a historical place," Huggard says of the neighborhood. Along with its proximity to the Boston Common and appeal to tourists, "it's got such a character to it," he said.

While telling the story of his restaurant chain's growth, Huggard was sure to give credit to partners Tobin and Higgins. In particular, Tobin's ability to draw from past experience in the pizza business was key. "He had a great recipe," Huggard says.

To that end, there's no doubt: in the Upper Crust recipe, Beacon Hill represents one of the most important ingredients.