The loch is home to St Tredwell’s Chapel, the ruins of which can be found on a small mound on a promontory jutting out into the murky waters. This has long been a site of pilgrimage, with structures here dating back to the Iron Age, with the more recent chapel built on top.

Legend has it that St Tredwell, or Triduana, gouged out her eyes and presented them to King Nechtan of the Picts after he praised their beauty. She was possibly laid to rest here, before miraculous cures for those suffering from eye problems quickly became associated with the waters of the loch. It’s said pilgrims from across Orkney and further afield travelled here looking for cures for their ailments.

The loch itself is home to a range of wildfowl and marsh plants, and is a pleasant walk south from the Papay Hostel and shop.