First of all, you are going to love Kerry, it's absolutely gorgeous!
There are a number of excellent equestrian centres around Kenmare and Killarney, including the ones mentioned by Belen.
I would also advise you to come and visit us at Eclipse Ireland
! We offer off-road trekking and lessons for beginners and advanced riders alike (flatwork, jumping or cross-country lessons available). As you can see in the picture below, the landscape around here is just stunning and it's a wonderful riding experience :)
And if you'd also like to try something adventurous after your trek, we offer nearly 20 activities such as kayaking, Mud Surfing, Bog Run, Assault Course, archery, Coasteering and Gorge Walking...
Hope to see you in September!
00 353 (0)64 66 82 965 http://www.eclipseireland.com/