Mourners from throughout Massachusetts and from across the nation will gather at historic Faneuil Hall today to honor Thomas M. Menino, Boston’s longest serving Mayor. It’s a fitting location, central to Menino’s 20 years in office: the site of his first inaugural, his last state-of-the-city address, as well as numerous award ceremonies for Boston Public schoolchildren.

Just eight months ago, Menino said farewell to Boston in Faneuil Hall. Today the public has its chance to say its goodbye to him.

At 9:40 Mayor Marty Walsh will lead a procession from the ultra-modern City Hall to the ultra-traditional Faneuil Hall. He’ll be accompanied by the Boston City Council; Mayors from across the state; state legislators; and a delegation of federal officials.

Starting at 10, Menino will lie in state. The city is urging people to use public transportation, as some of the streets surrounding Faneuil Hall are closed, and parking will be restricted on those that are open. Mourners are discouraged from bringing bags, and photography inside the hall is prohibited.

Across the street, City Hall will be open so people can add to the growing memorial of flowers, cards, pictures, and balloons. A Boston-area resident named Kelly says she came to sign the condolence book out of respect.

“And to say thank you because the mayor turned Boston around. And you feel safer when you come into Boston now. Just so many nice things have happened and it’s a shame that he died. He was a wonderful person.”

Monday, a big screen will be set up outside City Hall so people can watch the mass for the mayor.

A funeral procession will begin at Faneuil Hall and pass places of significance for Menino: the Parkman House on Beacon Street near the State House; Boston University, where Menino was a professor; Fenway Park; Dudley Square; Grove Hall; Franklin Park; Bowdoin Geneva; the Mattapan Library; and Roslindale Square.

The procession will conclude at Menino’s family parish, Most Precious Blood in Readville, where Menino was baptized and served as an alter boy. The mass is private.