Albert Barnes Commentary 2 Chronicles 32:33

"And Hezekiah slept with his fathers, and they buried him in the ascent of the sepulchres of the sons of David: and all Judah and the inhabitants of Jerusalem did him honor at his death. And Manasseh his son reigned in his stead." — 2 Chronicles 32:33 (ASV)

The highest of the tombs - Most modern commentators interpret this as “on the ascent to the tombs,” but some think it refers to an excavation above all the other tombs—in the same repository but at a higher level (see the margin). The catacomb of David was full, and the later princes had tombs quite distinct from the old burial place (see 2 Chronicles 33:20; 2 Kings 21:18, 26; 2 Kings 23:30).