RE: the Towers.

Thank you for the reply(s). They were in fact built by Elendil. With a little research I answered my own question. The three towers were built by Elendil. Called the Emyn Beraid or Tower Hills, they were built to house the Elendil stone. It's amazing to think that Lindon was so close to the Shire.
The little asides in LOTR are one of my favorite parts of the books: the towers, Gandalfs discussion of the Noldor and Feanor while he was carrying Pippin to Minas Tirith and Elrond discussing the Host of Beleriand during the Council come to mind. Before the Silmarillion was published these side discussions of the older history were highly intriguing. And of course, in the appendices at the end of ROTK
Tolkien states: as is told in the Silmarillion. The what? I COULD HARDLY WAIT.