The San Francisco Yacht Club Lighthouse 1. Stock Image

Going back to very early but wide spread water travel, light in the form of some kind of fire was used to signal the entrance of a port or harbor.This grew into the constructions of structures to house the light, along with some kind of lens system to direct the light further out to sea. With the increased cost of maintenance for these lighthouses, along with the common use of onboard navigational systems, the continued use of lighthouses has become impractical, causes many of them to be closed.