You have a street, but in York it would be called a "gate". You have a gate, but in York it is called a "bar". And of course just out of the picture you have bars, but they are called pubs. Good so far?
Specifically this is Bootham Bar. It stands on Roman foundations and in fact once was the northwest entrance to the Legionary fortress. Most of what you see is 14th century or later. It has seen its share of troubles, in times past the heads of traitors would be displayed here. In one of those historical tidbits that can lure you off into detours I found reference to the Bar being unsuccessfully attacked in 1487 by "Lord Scrope, on behalf of the Royal impostor, Lambert Simnell".
The road, sorry, Gate that goes through it was once the Via Principalis, the main road that ran past the Roman headquarters building. It continued on straight out of town. If you stay on it long enough and hang a left on the Stanegate just short of Hadrian's Wall, you will end up where I did a few days later, at the Vindolanda fort site.
A sign on the side of Bootham Bar indicates that in times past any "Scottish persons" who wanted admission to York had to use a special door knocker to request entry. This prudent precaution has been allowed to lapse in recent centuries.
At the other end of town we find a more elaborate barrier, the Monk Bar. Not exactly on the site of the former Roman entrance it is also 14th Century work. It still has the original mechanisms for lowering a wooden barrier called a portcullis. Although I must report that the actual portcullis is a modern construction.
A few more images of the Monk Gate...
Yes, York is an odd place. How odd? Observe.