The Fallen Lighthouse is a location in Bleak Inlet, it is iconic after being featured in game artwork and as the thumbnail picture for the region.
The despite it's notoriety, the lighthouse does not serve as a good safehouse, as it is not an enterable location (i.e., it does not present a loading screen upon entering), and thus it leaves the player exposed to cold and unable to cure hides, guts, or saplings. It also lacks a bed, workbench, and other useful features.
Despite these Iimitations, it can make a good temporary camp for those well-supplied with firewood and/or warm clothing. It is conveniently positioned near the Cannery Worker Residences (a better safehouse option), and its outdoor six-burner stove makes it an optimal location for efficient cooking and for cooking skill improvement. Nearby, deer and rabbit spawns can be found, in addition to ice fishing huts. It is a good place to spend a day or three, while probably spending the night somewhere else.
The Fallen Lighthouse provides a good view of the player's surroundings, only bested by the radio hut on the mountain. Although the aspects of the location and terrain around it would make for a good safehouse, it might be challenging for the player to make it through a night there, as the nights can get very cold and timberwolf attacks are possible.
Aside from this, It makes a somewhat good location for a base of operations, only sleeping somewhere else might be required.