Monach Islands

 ( Uninhabited Islands Of The Outer Hebrides ) 

Smaller islands in the group include Deasker (Deas-Sgeir), Shillay (Siolaigh) and italic=no (or Stockay).

The 19th century census records for the islands show a fluctuating population, from 39 people in 1841 up to 140 people at their peak population in 1891.

Shillay is the location of Monach Lighthouse, built by David and Thomas Stevenson in 1864. The lighthouse was closed in 1942 but, following the sinking of the oil tanker MV Braer in 1993, a new and much smaller lighthouse was built in 1997. This had a range of ; when a range of was deemed necessary, the new lighthouse was shut down in 2008 and the old lighthouse recommissioned with a new optic. Like all British lighthouses it is now unmanned and fully automated.

In 2007 renovations of the old schoolhouse were completed, enabling visitors to stay on the island, and learn about its history and wildlife. The old Heisgeir mailboat has also been restored at the Grimsay boatshed. The motorised open wooden boat was built circa 1932 for the last family to leave the Monach Islands, and had lain unused at Lochmaddy before being rescued by the local history society.

The islands are designated as a Special Protection Area (SPA), a Special Area of Conservation (SAC), and a Site of Special Scientific Interest (SSSI). The International Union for Conservation of Nature (IUCN) classifies as the islands (via the SSSI designation) as meeting the criteria for a Category IV protected area. The SAC designation extends to cover the seas surrounding the group, and in 2014 a larger area of the sea surrounding the islands (in total ) was declared a Nature Conservation Marine Protected Area (NCMPA). The designation is in place to protect the feeding grounds of the islands' seabirds, as well as the marine geomorphology of the seabed. The Monach Islands were also formerly designated as a National Nature Reserve, but this designation was withdrawn in May 2018.

• List of islands of Scotland