This started as a fork and continuation of DFYX's no longer maintained Landmarks plugin. He created a plugin that allows you to set landmarks in-game that will show up on Dynmap maps. Unfortunately the plugin was rather simple and is no longer maintained, resulting in breakage when dynmap updated.

I at first just fixed the compatibility issues, but ended up completely rewriting the plugin. This plugin picks up where the original Landmarks 0.2 left off and adds among other things the following features:

Support for the latest dynmap versions.
Support for the latest CraftBukkit RB's.
Support for Superperms / BukkitPermissions (and all other permissions plugins that support Superperms).
Improves landmark editing and maintenance.
Adds landmark groups/types and custom icons.
Adds a teleport command for landmarks (can be disabled/enabled through permissions on a per-landmark basis).
Adds a "look at" command for landmarks (can be disabled/enabled through permissions on a per-landmark basis).
Theoretical support for other map systems (at least one known implementation for PigMap).

Link to the latest plugin version
Link to the latest dynmap webfiles