Mr Key was welcomed under the hot Hawke's Bay sun at Woodford House and Iona College yesterday.
He told the Iona girls he loved their hats "very functional and stylish," while at the school to open two buildings.
He had heard many good things about the school from the former National Party president and Iona old-girl Judy Kirk.
While the buildings were great new learning centres he said it was the culture of the school, the values that underpin it and the camaraderie that made the school.
"You get out of life what you put into it. Just have big dreams. When I was 11, I wanted to be Prime Minister of New Zealand."
Iona College Principal Shannon Warren said it was a "dream come true" for a principal to have two new buildings to open - the Information Resource Centre and the Blyth Performing Arts Centre.
The substantial building projects kicked off in March 2013, 100 years after construction of the original Spanish-mission-styled school.
Spread over three levels, the Information Resource Centre consists of a library, an information tecnology centre, an English department and a Year 13 common room. The performing centre features a 400-seat auditorium with professional concert acoustics. The buildings were made possible by a generous gift of Old Girl, Margaret Blyth.