The memorial is located on a hilltop on the Mull of Oa (The Oa Cliffs are the most southern part of the Isle of Islay). The memorial is about 1 mile south west of the road-end.

The American Monument is built on a 429 foot (131 metres) high cliff on the Oa Peninsula in 1920 by the American Red Cross, and is designed by architect Robert Walker. The monument commemorates the loss of two troopships in 1918, the Tuscania and the Otranto and the location overlooks the very spot where the Tuscania sunk. The monument is built in the shape of a lighthouse and is visible from many areas on Islay.

The monument itself has two plaques. A large one on the east side of the monument which looks like an entrance door, and a smaller one on the seaside in front of the monument.

The Tuscania, a passenger liner, was on its way from New Jersey to the coast of France with 2,000 American soldiers and a crew of more than 300. At Halifax, Nova Scotia, they joined a convoy and entered the British waters between Islay and Northern Ireland on February 5, 1918. The convoy was followed by a UB-77 German submarine which torpedoed the Tuscania. The direct hit on the Tuscania resulted in heavy damage and the Tuscania sunk after a few hours, 7 miles off the Islay coast near the Oa peninsula. An estimated 230 lives were lost in this tragedy.

Eight months later, on October 6 1918, another tragedy occurred only a few miles from the place where the Tuscania sunk. The HMS Otranto was carrying troops from New York to Glasgow when it collided with the steamship HMS Kashmir during a heavy storm. This tragedy took place not far from Machir bay on Islay's west coast. Over 400 lives were lost, both British crew members and US servicemen. Many of the victims were buried at the Kilnaughton Military Cemetery

One American, Private Roy Muncaster served in D Company, 6th Battalion of the 20th Engineer Regiment, “Fighting Foresters”, still lies in the nearby Kilnaughton Military Cemetery. See site Kilnaughton Military Cemetery for more on this Isolated Burial.

 Source:

 IslayInfo.com

https://www.iwm.org.uk

Larger plaque:

Sacred to the immortal memory of those American Soldiers and Sailors who gave their lives for their country in the wrecks of the transports Tuscania (feb 5th 1918) and Otranto (October 6th 1918). The monument was erected by The American Red Cross near the spot where so many of the victims of the disasters sleep in everlasting peace.

On Fame's Eternal camping ground
Their silent tents are spread
While Glory keeps with solemn round
The bivouac of the dead

Smaller plaque:  

A tribute from Woodrow Wilson, President of the United States of America. To the memory of his fellow citizens who gave their lives for their country in nearby waters, dated 1918.