This dim and damaged painting is from the eave of a house in Nauplion -- take the street to the left of the bus station, first corner to the right -- to my knowledge, the only remaining 19th-century house with eave-paintings left in the city.
Other houses, much restored, have these curved eaves but they show stenciled ornamentation: pre- and post-independence ornamentation made extensive use of stencils. This house, built shortly after 1830, has hand-painted swags of flowers, a parrot, and this exceptional view of the walls of Nauplion with columned buildings that were never there. At that date, Nauplion's walls were mostly wrecked, and the remaining towers were of a different design. In fact, most pre-modern views of Nauplion show buildings that no one who lived there would ever recognize: Venetian images have Venetian houses from the terraferma, and later artists show Ottoman fantasies, but the eave painting seems to have been influenced by an image from a popular book.
This book published by G. N Wright in 1840 and called The Shores and Islands of the Mediterranean included a steel-engraving of a view of Nauplion from the water -- a detail here. When the image is enlarged, you can see a number of white-columned buildings, pediments, acroteria -- the various signals of classical Greek architecture. A Nauplion painter, then, saw the picture -- or the owner of the house had a copy of the picture -- and it was used for the wreathed cartouche over the front door of the house.
A second image, or one of the many derived from it, possibly contributed a tower to the cartouche -- the Camoccio map excerpted here several times previously. The artist of Shores and Islands never saw towers like this at Nauplion: this is a 15th-century design for defense against small shipboard cannon. Those towers were built about 1700 for a different kind of defense, when the harbor was too shallow for the high-decked ships of the period to come in close enough to be of danger.
Those small black keyholes in the towers are sighting blocks for small cannon. You can see several of them in the walls at Methoni, but Nauplion has only one left and that one is upside down, in a tower by one of the swimming clubs past the end of the waterfront. But it is possible that the tower of the cartouche was painted from one of the towers up on Akro-Nauplion.
The configuration of the largest street in Nauplion follows the line of the walls in this engraving. The street that ends at the Bibliotheke Palamidi occupies the space where this (actually, straight) harbor wall stood. Where the print shows water and wooden piers, there are now schools, hotels, Hermes Car Rental, the Peloponnesian Folklore Museum, Savouras Restaurant, and others. Much of Nauplion is built on landfill, intentionally as of 1480 and the Venetians, from silt brought down by a stream that disappeared in the 19th century, and in the last decade from a vigorous program of fill and construction.
That is all concrete and corners and has nothing to do with this small proud crumbling cartouche of an idealized city, the capital city of a free Greece with its mighty protective walls and the columns of its glorious heritage.
Dimitrios Antoniou called my attention to the content of this cartouche, an image I had photographed but not thought about. The 1840 Nauplion engraving is found in The Nauplion of the Foreign Travellers by Aphrodite Kouria, a 2007 publication of the National Bank of Greece available in, among other places, the gift shop of the Peloponnesian Folklore Foundation in Nauplion.