Sandwith Place was off Sandwith Street, but unfortunately it's not listed in the street listings on Thom's 1877 or 1879, which sometimes happens with the smaller side streets and lanes, especially if there were no businesses, public buildings or prominent individuals living on the street.
You can see Sandwith place just north of Gt. Brunswick Street (now Pearse St.) on the c1890 OSI map -
Sandwith Place (select the 25" historic option for a c1890 map)
The earliest details I've found for Sandwith Place are from the building returns on the 1901 census - although the street could have changed a bit by then. In 1901 there were about 39 buildings, most of which seem to be smallish houses with 1, 2 or 3 windows in the front, many of which are shared by 3 or more families.
There doesn't appear to be any businesses or shops on the street at that time. In 1901 there are total of 62 families living on the street consisting of 304 people.
Great Clarence place was off South Great Clarance Street (there's another Clarence St northside) off Grand Canal street. It's the opposite side of Gt. Brunswick Street - so very close to Sandwith Place. see
Great Clarence PlaceShane
