The Mire Road Gates.
The Mire Road Gates were the entryway for The Great Mire Road on the Undertown side.
Between the two towerposts of the gates were Tally-Huts. To pass through the gates, a traveller was required to present an official document to a Shryke Tally-Hen, stating the reason for journeying / having jouneyed across the Mire (eg. timber merchant from the Foundry Glades), before being permitted to pass through.
As the Mire Road was the foremost path of trade from the Deepwoods to Undertown in the Second Age of Flight, the square before the gates represented an opportune and ideal market-place for venders and merchants to convene, who could offer their produce to the thousands of travellers departing from, and arriving to, Undertown.