Doon (Irish: An Clochán) is a small hamlet in the north-west corner of County Offaly, Ireland. The Doon landscape is dominated by the ruins of the castle of Esker, which stands on a sandy ridge north of Doon crossroads. A short distance to the east of the crossroads stands the ruin of an ancient building know locally as 'the monastery'. It was the private religious house attached to the castle. The hamlet today thrives principally thanks to its friendly, mostly farming community, whose needs are serviced in no particular order by the local shop, the pub "Martins" of Doon and by its Gaelic football pitch, the home pitch of Doon GAA, and training ground for those within the surrounding catchment area.