Milton is not much commemorated by public memorials compared to other English poets of comparable fame, to say nothing of lesser stature. There are a number of obvious circumstances that this post should illustrate which will explain this dearth; nonetheless the almost complete absence of any physical reminders of Milton, as well as of the many other great authors of his age and the one preceding it, when their writings remain so grand and vivid and central to the imagination of anyone who has read them to any extent, is still a notable omission to such a visitor upon arriving in modern London especially.
Milton was born on Bread Street in Cheapside, in the old City of London, in 1608. Though only a block long, Bread Street had a distinguished literary history. John Donne was also born on the street in 1572, and the legendary Mermaid Tavern, one of the main hangouts of Shakespeare, Marlowe, Ben Jonson and other luminaries of the rollicking Elizabethan period, was situated on the corner at the bottom of the street. All remnants of this neighborhood of course are long, long gone, having been destroyed in the famous London fire of 1666, within Milton's own lifetime. Whatever was built to replace this seems to have been summarily bombed out during the 2nd World War, and while a Bread Street continues to exist today, it is little more than an alley, non-residential, and such modern office and institutional buildings as do line it showing their backs and sides to the pedestrian, the various ways into them being found on other streets. I walked up and down this ugly and depressing, though mercifully short block three or four times, figuring surely there must be some memorial to the great writers born there on it. However I found nothing, and wanted up to the larger avenue known as "Cheapside" and took a right, headed I forget where. The old church of St Mary-le-Bow--that is the one which one must have been born within hearing distance of its bells if he wanted to claim himself a true Cockney--was right around this corner, so we took a little walk around the outside of it, it being around 6 o'clock in the evening so all of its doors were locked, and we came upon this:
We never did come across any commemoration for poor old John Donne however, though he does at least have a prominent tomb in St Paul's Cathedral, where he was for many years the rector (at the old one which was destroyed in the fire of course).
Milton was buried at the minor church of St Giles Cripplegate at the east end of the old city. Due to his active participation in the Cromwell government--he was its official Latin secretary--and general antagonism to the Stuart monarchy he was decidedly out of favor with the authorities of the Restoration at the time of his death and was thus not a candidate for burial in any of the glamour churches, which position has been more or less upheld to the present day, there not being still I believe any commemoration for him in Poet's Corner, which other once-rejected authors, notably the libertine Romantic poets, though still buried elsewhere, have since been given.
St Giles Cripplegate has been preserved, though the ground around it has been completely bricked up and serves as the courtyard for a modern office park-like complex. Not being very adept at using a camera and crimped for space by the boundaries imposed upon the open space before the church by the office buildings, I could not figure out how to fit the entire church in a single shot, so you will have to visualize the two halves following combining themselves: