The Alwars (also spelled Azhwars) are a group of 12 ancient Vaishnava saints who lived in Tamil Nadu and are famous for their poetry in praise of Vishnu. One of the Alwars was Thirumangai Alwar, aka Parakala. At various points in his life, he was a chieftain and a robber. And he met Vishnu on multiple occasions. First of all, Vishnu personally did the Samashrayanam ritual for him in the Nachiyar Koil Vishnu temple in Thirunaraiyur. Second of all, during his robber phase Lakshmi and Vishnu appeared to him as a bride and groom. But I just found a third such incident.
The Divyasuri Charitram is a work by the Sri Vaishnava Acharya Garudavahana Pandita, a shishya of Ramanujacharya, about the lives of the Alwars. This journal paper summarizes an incident described in the Divyasuri Charitram involving Thirumangai Alwar:
Once on his way to Venkatam, Parakala and his retinue were hungry and thirsty. At that time they encountered an old Vaishnava who bore on his forehead the urdhva pundra or mark of Vishnu. Parakala asked him if he could tell him from his holy books what destiny held for him, and to give them what food he had on his person.... The old Vaishnava, who was Vishnu himself in disguise, told him that his future would be harimaya (filled with the Lord), and then distributed the delicious food he was carrying to the Alvar's party - a mere handful each of which satisfied them entirely. Parakala then asked the brahmana who he was. Here the text says significantly, "Since the Lord is always in the vasa, bondage, of Vaishnavas, He gladly answered.” Thus, the brahmana replied that he was a resident of western Kanchi, by the name of Ashtabahu Narasimha, and so saying, vanished.
My question is, what is the location where Thirumangai Alwar met Ashtabahu Narasimha?
The parts in bold may give a clue. It says on his way to Tirupati, and Narasimha told him he was a resident of Western Kanchipuram. Now Thirumangai Alwar is from the Sirkazhi area, and Kanchipuram is on the the way between Sirkazhi and Tirupati. So did they meet in Kanchipuram? If so there are at least two relevant temples in the Kanchipuram area: the Ashtabhujakaram temple, where Vishnu has eight hands, and the Thiruvelukai temple, which is a Narasimha temple, albeit one where Narasimha has four hands and not eight.
In any case, do any Sri Vaishnava works shed light on where this happened?