Philip Somervail • Link
Here's a link with descriptions of various buildings in the City of London in 1731, including five of the eight gates (now all long-since demolished, sadly) - being Aldgate, Bishopsgate, Aldersgate, Newgate and Ludgate: http://www.globusz.com/ebooks/Lond1731/00000012...
Maybe illustrations of them can be found on the web as well? (The Encyclopaedia of London  has pictures of them, however.)
Philip Somervail • Link
...and here's Aldgate's location (and many thanks to Susanna for finding this 1746 map of London online): http://www.motco.com/Map/81002/SeriesSearchPlat...
Interesting that Jewry St. was then Poor Jewry Lane,
and that there was a Goodman's Yard but no Portsoken St. off the Minories. Does anybody know of a comprehensive book on the history of London streets comparable to Hillairet's Dictionnaire historique des rues de Paris? (Which I highly recommend:
Martin K. Foys • Link
Aldgate and Chaucer
Aldgate was also the home of Geoffrey Chaucer, who had an apartment in the southern section of it, and likely did much of his writing there before retiring to Greenwich.
Jewry Street today runs along the line of the demolished medieval wall; it also runs straight into Crutched Friars Street, which would have been quite a strange juxtaposition medieval times.
View of Aldgate incorporating flat topped towers and a window over the central arch. 1800? © City of London
Aldgate, a gate in the City wall towards the east, and, according to most authorities, called Aldgate from its antiquity or age, but in the earliest records the spelling is Alegate (1325-1344), or Algate (1381), which is suggestive of another derivation. The gateway, a stately structure, stood in the midst of the High Street, south of Aldgate Church. Duke's Place and Poor Jury Lane—now called Duke Street and Jewry Street—being immediately inside the gate and wall. In 1215 the barons who were at war with King John entered the city with ease at Aldgate, which was then in a ruinous condition. Shortly afterwards they rebuilt the gate.
In 1374 a lease was granted for the term of his life to Geoffrey Chaucer of "the whole of the dwelling-house above the gate of Algate with the rooms built over, and a certain cellar beneath the same gate, on the south side of that gate, and the appurtenances thereof," he undertaking that he "will competently and sufficiently maintain and repair" them under penalty of being "ousted" on the neglect to do so.
---London, Past and Present. H.B. Wheatley, 1891.
Chart showing the number of references in each month of the diary’s entries.