From the Super Mario Wiki
Poshley Heights is a posh village that Mario travels to by riding the Excess Express to get the Garnet Star, in the game Paper Mario: The Thousand-Year Door. It is also the home of many wealthy celebrities, including Goldbob and Toodles. It also has very expensive items. Many Bumpties live here as well. Lady Bow and Bootler vacation here after Mario and company defeat the Shadow Queen. Sir Grodus, Lord Crump and the X-Nauts are also shown to have ended up in Poshley Heights after the Shadow Queen's defeat, however, when Mario goes to the place where they can be seen in Goombella's e-mail, they can't be found there.
Poshley Heights has the only inn in Paper Mario: The Thousand-Year Door that has more than one room (not counting Rogueport). This inn is similar to the Marrymore suite from Super Mario RPG: Legend of the Seven Stars.
The in-game map description reads, "A town famous for all of the rich and famous people living in it. There are plenty of extravagant vacation homes and hotels in town."
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