[Leaning Right]

> How were they seen at night? <

A small tower was built near each arrow. A spotlight in the tower illuminated the arrow. Those towers are all gone now.

[ProtectOurFreedom]

The light on Mt. Diablo in California remains. It is mounted on a a beautiful stone tower on the summit of the leak, not a steel tower, but it was a key element in that navigation system.

It was completely restored a few years ago and it is lit annually on December 7. It was extinguished in December 1941 for obvious reasons and stayed out until 1964 when it was relit in honor of those who died in WW II.