A 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). They are unlisted in any official directory, and their doors are marked only by a room number). Hideaways are assigned to senators based on seniority, and they range from lavish and expansive upper-floor offices to small, cramped offices in the basement). 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. Hideaways are assigned by the Senate Rules Committee based on seniority, and the offices assigned to the most senior senators are often lush and expansive).

Despite their name, hideaways are not necessarily secret or inaccessible to others. In fact, many hideaways are open to staff and other trusted associates of the senator, who can use them as a place to work, brainstorm, and collaborate. Some senators even host small receptions or meetings in their hideaways, using them as a venue for informal gatherings and social events.

The location of hideaways is not disclosed by the Senate Rules Committee, and many spacious hideaways sit behind nondescript-looking doors. The best hideaways go to the senators with the most seniority, and the selection process for new hideaways begins after the senators finish picking their office building suites.

In summary, a 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. Although they are not necessarily secret or inaccessible to others, their locations are not disclosed by the Senate Rules Committee.