Machair or machar is a GÃ idhlig ( Scottish Gaelic ) word used to describe a fertile low-lying grassy plain found on some of the north-west coastlines of Ireland and Scotland , in particular the Outer Hebrides . The Gaelic word machair or machar refers to a fertile low-lying grassy plain found on some of the north-west coastlines of Ireland and Scotland , in particular the Outer Hebrides .