Refers specifically to the tall slender tower of a mosque, from which the call to prayer is given. The kanji 光塔 literally means 'light tower'.
See also: ミナレット
The call to prayer can be heard from the mosque's minaret.
A Japanese-coined word combining 光 (light) and 塔 (tower), likely created to describe the tall tower of a mosque, which is often illuminated or associated with spiritual light.