The Tower of Barbs is the main setting of Let It Die. It consists of 40 floors, each of which consists of one or more areas. The name of each area is reminiscent of a Japanese neighbourhood, which it probably once was, and has now been pushed upwards into the tower. Areas between floors are connected to one another by escalators.
Many floors are accessible via the main elevator or one of several secondary elevators, once the player reaches the elevator door from the outside and throws a switch to unlock it. Riding the regular elevator costs a number of Kill Coins commensurate with the distance to be travelled (the Kill Coins must be on the Fighter's person, not stored in the bank); the golden elevator operated by Torai Rin is accessible only to Direct Hell Express members in exchange for real-world money, but can be used as often as desired.
The Tower is most of what is left of human civilization following the Earth Rage tectonic event that unleashed worldwide catastrophe. It is located on a tiny island centred on what was once Toukyou, Japan, the remnants of which can be seen throughout the tower: Sections of it were clearly once busy train stations and tunnels; many outside areas are the smashed remains of typical Japanese suburbs; the famous 109 Building in Shibuya can be seen uprooted and plastered to the outer wall; and so on.
Many theorize that the Tower actually has no fixed peak, and will simply continue to grow taller if any individual approaches it. However, this appears to be untrue as the player character summits the 40th and final floor.
At 00:00 GMT (4PM PST, 5PM MST, 6PM CST, 7PM EST) every day, the layout of the tower and which areas are available changes. There are four different rotations that are cycled through repeatedly. Most of the centrally located areas exist in all rotations with some exceptions, though they may move around on the map as their connections change. For every rotation there are a number of areas that are only available during that rotation, which means that the player can only enter them one out of every four days. Some of these rotation-specific floors may have Stamps, pages from Tales From The Barbs, or pages of the Yotsuyama Bionics Catalogue.