Hammerfall doesn't have one, but Yokuda had Orichalc Tower.
I like the idea of opening up the possibility of Towers on other continents. Vampire Snake-Man Tower, anyone?
(OK, I'll stop with the Tsaesci fetishism now).
My list of Towers is:
-ADAMANTINE TOWER -- The Ur-Tower, Akatosh's spaceship and the place where the Convention was held and the divine rule of law cast (sort of) as Lorkhan's Heart was cast into exile. Home of the Zero-Stone, of which all other Stones are myth-echoes. On the Isle of Balferia in High Rock.
-RED MOUNTAIN -- The Tower in Morrowind, the massive volcano that dominates and, in a larger sense,
composes the Isle of Vvardenfell. IIRC, it's the most important Tower, or one of the most important, because its Stone is the Heart of Lorkhan, the Heart of the World.
-WHITE-GOLD TOWER -- The Tower at the heart of Tamriel geographically, whose Stone is Chim-el Abadal, the Amulet of Kings. The function of this Tower's creatia stream seems to be tied to the line of Tamriel's rulers and, most recently, to the Dragon Statue. But, most importantly, its shape is a myth-echo of the Aurbis, which holds some kind of (possibly eschatological) significance.
-WALK-BRASS -- The Dwemeri Tower, a giant god golem, whose Stone has varied -- at first the Heart of Lorkhan, and later the mysterious Aetherial Mantella jewel. It has no set location, being an animated god construct, and its creatia stream can be directly commanded, ripping apart the very fabric of Mundus's reality (no doubt much to the dismay of the Jills, who have to clean up the mess afterwords).
-SNOW-THROAT -- High Hrothgar, the Tower of the mysterious Falmer. It is the giant mountain that serves as the focal point of Skyrim, from which Shor breathed life into the People of the Sky. The mountain goes high into the air and is covered by cloud cover -- it is said that parts of it do not exist in the same reality. The Thu'um dudes practice here, I think.
-CRYSTAL-LIKE-LAW -- The Crystal Tower of the Altmer, in the heart of the city of Alinor. Unknown Stone; however, it is said to contain records extending to the Merethic Era, and the remains of High Kings past, among other things.
-GREEN SAP: The walking city of Falinesti, a giant tree that likes to walk around and serves as a home for an entire population. Unknown Stone; has recently rooted itself without explanation.