Ysbyty Cynfyn was a hospital of the Knights Hospitaller of the Order of St. John of Jerusalem.

As a Hospitaller commandery, Ysbyty Cynfyn was founded in the 12th century, during the time this area of Ceredigion was ruled by Normans. It is on the road to what is now Strata Florida Abbey, though the first abbey there wasn’t called that initially.  https://www.dailypost.co.uk/news/north-wales-news/archaeologists-think-theyve-found-lost-28672014

It consists today of a church, dedicated to St John, situated within a wall that incorporates ancient standing stones.

This is one of three standing stones built into the churchyard wall. Their presence indicates that the medieval church may have been built over a pagan site.

The fact that the churchyard is circular is a further indication that worship has taken place here for possibly thousands of years.

On the other side of the Rheidol gorge (accessed by a stiff hike, not for the faint of heart!) are the remains of a bronze age burial mound that has eroded away to reveal the stone circle that formed its base. This combination of the standings stones and burial mound might have been part of a greater complex of prehistoric sites in this area.

The name Cynfyn, however, comes from a medieval King of Powys. Hospitaller commanderies can be found in Wales in places where the word ysbyty, which means hospital in Welsh, is attached to a church, particularly one dedicated to St. John, as is the case at Ysbyty Cynfyn.

There are indications that the Hospitallers took responsibility for their first churches in Wales as early as 1115, shortly after the founding of the Order. Although this church was rebuilt in the 19th century, no trace of the commandery or infirmary is left except for the name itself to indicate Ysbyty Cynfyn was once a Hospitaller commandery.