Most of our hiking and climbing, often even kayaking, in Ireland is thanks to the goodwill and generosity of land owners, often farmers – giving us access to their land and mountains.
Nice to say thank you from time to time 
Asking permission beforehand, passing the time of day with the landowner, thanking them for the access when meeting them on the hill – all cool things to do.Good Article On Access, From Mountaineering Ireland, Here: https://www.mountaineering.ie/content/AccessInIreland/189 + https://www.mountaineering.ie/content/AccessPolicy/204