I question the notation of this section of Hingham being called "Old Spain". References to that "Old Spain" in the area are attributed to North Weymouth which is a short distance away. See the following:
https://www.weymouthhistoricalsociety.org/pdf/historical_sketch_chap01.pdf
Weymouth, commonly known as "Old Spain," extending from the shore of the bay to Burying Hill...

Walnut Street is private property and the owner challenges you to walk there.