Before the simplification of forms, turrets made corners a point of interest, emblems of spectacular craftsmanship and ambition.
Those architectural features most unique are frequently the most expensive to maintain. Many turrets have been shamefully re-clad or beheaded--stripped of their essentials.
The Witch's cap or Candle-Snuffer roof remains (second image), though the fenestration has been depredated by an aluminum skin.
In high occupancy situations, sometimes turrets, meant to function as adjunct sitting rooms--offering the grandest views, are converted to closets.
Resourceless tradespeople often resort to "mummifying" conical forms, with tar paper or roll products.
Adding insult to injury, most decapitations yield poorly flashed, flat-roof sections which hasten other (water-related) degradations.