A Capitol hideaway office is a personal, unmarked office in the U.S. Capitol building used by members of the Senate and by a few senior members of the U.S. House of Representatives). These offices are not listed in any official directory, and their doors are marked only by a room number. Senators use hideaways as a private space to prepare for sessions of the Senate, conduct confidential meetings, take naps, and for other personal purposes). They are often conveniently located near the Senate floor and range from lavish and expansive upper-floor offices to small, cramped offices in the basement). Hideaways are assigned to senators based on seniority, and the history of hideaways dates to the earliest occupancy of the U.S. Capitol in 1800).

The secrecy surrounding hideaways has generated considerable media interest, with provocative article titles, such as "Senates Biggest Secret: Lush Hideaways for Lawmakers" and "Congressional Perks: How the Trappings of Office Trap Taxpayers". The location of an individual senators hideaway is a closely held secret, with most having no names on the doors and hidden from view, with some even tucked away behind large statues.

In terms of appearance, hideaway offices can vary widely in size and quality, with veteran lawmakers snagging plush space with sweeping views of the National Mall and newbies getting windowless basement digs. Some of the smallest and oddest hideaways are windowless, cramped quarters in the Capitol basement, while some of the best hideaways are on the first and second floors and have soaring ceilings and walls painted under artist Elmer Garnsey at the turn of the 20th century. A precious few have fireplaces, bathrooms, or huge windows.

In summary, a Capitol hideaway office is a private, unmarked office in the U.S. Capitol building used by members of the Senate and by a few senior members of the U.S. House of Representatives. They are assigned based on seniority and are used for a variety of purposes, including preparing for sessions of the Senate, conducting confidential meetings, and taking naps. The location of an individual senators hideaway is a closely held secret, and hideaway offices can vary widely in size and quality.