I noticed some countries have a lot of national identity/symbols for stamps and I feel like there is so many more stamps you could have for Ireland.

The GPO (General Post Office) in Dublin I think would look really well on a stamp, it also has a huge importance in our history as well as it's a post office so why not? :D

Other little things like a Harp stamp would be nice (the harp is our national symbol)

The Ha'penny Bridge.

Dublin Castle.

The Cliffs of Moher.

Newgrange Tomb.

(Which is older than both Stonehenge and the Great Pyramids of Giza)

Skellig Michael could also look well on a stamp, (it was even featured in star wars)

I know I've seen it on the Slowly World Explorer.

Maybe even if you could make the little beehive huts from the island on a stamp that would look well :)