Many of these structures were listed on the National Register of Historic Places in 1991, using the alternate spelling "Tomhum".

There are three pillboxes on or near the beach of Tumon Bay, all made from concrete mixed with coral limestone.

The first is a partially-collapsed concrete structure between the Hyatt Regency Guam and the beach; it has two embrasures providing gun placements facing north and west.

[5] Cliffline Fortification Two is a series of hand-dug caves excavated out of the limestone cliffs.

The largest of these is 17.5 metres (57 ft) in length, with limestone pills for support, and is the only one showing evidence of use by the Japanese.