Is there a functional reason for wizards to live in towers so often?
D&D (& most modern high fantasy) was heavily influenced by LOTR. Saruman lived in Isengard (a tower), therefore the common modern high fantasy trope is that wizards live in towers.<p>Here’s a thread explaining why Saruman lived in the tower of Isengard. 
<a href="https://www.reddit.com/r/AskScienceFiction/comments/33b4v3/lotr_why_does_saruman_have_a_tower_what_was_it/?utm_source=share&utm_medium=ios_app&utm_name=iossmf" rel="nofollow">https://www.reddit.com/r/AskScienceFiction/comments/33b4v3/l...</a>