Just a few:

• 1.080 Laid low their towers and houses frail.
• 4.035 into a tower of blue glowing smoke,
• 7.036 and towering tall above Gandalf.
• 7.151 overlooked by his dark tower!
• 11.001 towering grim
• 11.006 the grey ruins of ancient houses, towers, and walls.
• 19.011 “And bright are the windows of Night in her tower.”