Constantine is one of only two places in Cornwall to have a church dedicated to St Constantine, the other being near Padstow, and nobody really knows who St Constantine was.
Most sources suggest that St Constantine is likely to have been a chieftain, prince or king in the 6th Century. He is said to have been a violent man, but after his conversion became a monk and a missionary.
The church was built between 1420-1480 but there is evidence of an Iron Age settlement, and it is thought that the church is built on an ancient mound on top of the remains of a Celtic monastery.
The cache you are looking for is a small plastic bottle. There are houses nearby so you'll need to be fairly stealthy.
Congratulations to portloe1 on FTF