Boyd’s Bible Dictionary:
(thrown down). A westward gate of the temple at Jerusalem (1 Chron. 26:16).
Concise Bible Dictionary:
A gate “by the causeway of the going up” (1 Chron. 26:16). The “going up” doubtless alluded to a pathway that ascended from the lower part of the city to some entrance of the temple (compare 1 Kings 10:5). Such a causeway can still be traced, but it is hidden, under the houses built in the valley.
Jackson’s Dictionary of Scripture Proper Names:
casting forth