We are final planning stages for our grand 25 day tour around Ireland (July into August). I am working on our list of sites/attractions that we need to (because they sell out) and are advisable to (if we want to go at our selected time to keep to our schedule) pre book/purchase. We are touring the entire Island from Dublin all the way around to Northern Ireland and back to Dublin. Our route is mostly coastal. Most of us have been numerous times before but it's been awhile and none of us remember having to prebook anything including the nights lodging. So this is a different trip for us.
Already booked: Skellig Michael, Aran Islands Transportation;
Planning on booking: Book of Kells, New Grange, Kilmainham Gaol;
Purchase first thing in AM day of : Carrick on Reed Rope Bridge.
My general questions are: What sites/boats do you need to book? What sites/boats are go ahead and prebook for peace of mind? Sites you wished you had prebooked because a giant tour bus just dropped off 5 dozen people just before you got to the ticket line? I realize this is a very open ended question and I have not shared our specific itinerary with the forum. I am really looking for your "Top 10 Places to Prebook in Ireland" list based on your personal experience. Thanks in advance.