Never seen nesting swallows here, but when I was a kid (30-odd years ago!) there were loads of house martin nests in the eaves of the 30s semis on the roads between Stanstead Rd and Perry Vale. You could watch them flying too and fro with mud balls, and then see them peeping out of the holes in the nests.

Unfortunately, I think a lot of more recent householders have put up netting across their eaves to prevent the martins building their unapproved extensions... but you might still see a few if you wander down that way.