This is the entrance to the Monastery at Glendalough, founded by St. Kevin in the 6th Century.
The main entrance wall which separated the monks from the outside world
was accessed through this double-arched gateway.
It was probably built between 900 and 1200.
Here's the amazing part--
There is no mortar to support the arches in this gateway.

FRIDAY'S FOTO

We visited Drumcliff Cemetery in County Sligo, Ireland
and paid homage to William Butler Yeats who is buried there.
But it was this tombstone and its sentiment that moved me.
Its sentiment is at once poignant and hopeful.