The Nilai-Kanai Guardian Towers (ニライ・カナイガーディアンタワー?) are a series of ancient superweapons associated with the Nirai-Kanai Gādian TawāNilai-Kanai Temple. They first appear in the 1997 Toho film, Rebirth of Mothra II.
The Nilai-Kanai Guardian towers resemble dragon statues superficially, but this belies their true nature as weapons. The towers hold giant stones in their bases (most likely emeralds) which can fire powerful beams, and also allow the towers to move around despite their remarkable weight.
As Mothra Leo battled Dagahra and became overwhelmed by the latter's Barem manipulation, the hologram of Princess Yuna realised that Leo needed help to hold off Dagahra while the kids searched the Nilai-Kanai Temple for the Ghogo. Utilising her powers, she summoned the towers to action. At once, the two Guardian Towers rose out of the ocean, and began firing their beams at Dagahra, forcing him back and buying Mothra Leo vital time.