Glass floor

[2] On occasion, transparent display cases are built into the floor, such as in the Museum of Sydney in Australia, where the remains of drains and privies are shown in their original context, along with other archeological artifacts.

At 4000 feet (1219 m), the highest glass floor above ground is the novel outdoor application of the Grand Canyon Skywalk, operated by the Hualapai Indian tribe.

[citation needed] The highest above ground level in a freestanding structure is in Lotte World Tower in Seoul, South Korea at 1,568 feet (478 m).

[5][6] Some new planetariums now feature a glass floor, which allows spectators to stand near the center of a sphere surrounded by projected images in all directions, giving the impression of floating in outer space.

For example, a small planetarium at AHHAA in Tartu, Estonia features such an installation, with special projectors for images below the feet of the audience, as well as above their heads.